diff --git a/pandas-stubs/core/frame.pyi b/pandas-stubs/core/frame.pyi
index 59a0937a2..dc39ca8c1 100644
--- a/pandas-stubs/core/frame.pyi
+++ b/pandas-stubs/core/frame.pyi
@@ -38,6 +38,7 @@ from pandas import (
     Timestamp,
 )
 from pandas.core.arraylike import OpsMixin
+from pandas.core.base import IndexOpsMixin
 from pandas.core.generic import NDFrame
 from pandas.core.groupby.generic import DataFrameGroupBy
 from pandas.core.indexers import BaseIndexer
@@ -92,6 +93,7 @@ from pandas._typing import (
     ArrayLike,
     AstypeArg,
     Axes,
+    AxesData,
     Axis,
     AxisColumn,
     AxisIndex,
@@ -197,6 +199,8 @@ class _iLocIndexerFrame(_iLocIndexer, Generic[_T]):
             | tuple[slice]
         ),
     ) -> _T: ...
+
+    # Keep in sync with `DataFrame.__setitem__`
     def __setitem__(
         self,
         idx: (
@@ -209,7 +213,7 @@ class _iLocIndexerFrame(_iLocIndexer, Generic[_T]):
         ),
         value: (
             Scalar
-            | Series
+            | IndexOpsMixin
             | DataFrame
             | np_ndarray
             | NAType
@@ -273,6 +277,8 @@ class _LocIndexerFrame(_LocIndexer, Generic[_T]):
     ) -> Series: ...
     @overload
     def __getitem__(self, idx: tuple[Scalar, slice]) -> Series | _T: ...
+
+    # Keep in sync with `DataFrame.__setitem__`
     @overload
     def __setitem__(
         self,
@@ -284,7 +290,7 @@ class _LocIndexerFrame(_LocIndexer, Generic[_T]):
             | NAType
             | NaTType
             | ArrayLike
-            | Series
+            | IndexOpsMixin
             | DataFrame
             | list
             | Mapping[Hashable, Scalar | NAType | NaTType]
@@ -328,7 +334,7 @@ class _AtIndexerFrame(_AtIndexer):
             | NAType
             | NaTType
             | ArrayLike
-            | Series
+            | IndexOpsMixin
             | DataFrame
             | list
             | Mapping[Hashable, Scalar | NAType | NaTType]
@@ -800,7 +806,74 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
     def isetitem(
         self, loc: int | Sequence[int], value: Scalar | ArrayLike | list[Any]
     ) -> None: ...
-    def __setitem__(self, key, value) -> None: ...
+
+    # Keep in sync with `_iLocIndexerFrame.__setitem__`
+    @overload
+    def __setitem__(
+        self,
+        idx: (
+            int
+            | IndexType
+            | tuple[int, int]
+            | tuple[IndexType, int]
+            | tuple[IndexType, IndexType]
+            | tuple[int, IndexType]
+        ),
+        value: (
+            Scalar
+            | IndexOpsMixin
+            | Sequence[Scalar]
+            | DataFrame
+            | np.ndarray
+            | NAType
+            | NaTType
+            | Mapping[Hashable, Scalar | NAType | NaTType]
+            | None
+        ),
+    ) -> None: ...
+    # Keep in sync with `_LocIndexerFrame.__setitem__`
+    @overload
+    def __setitem__(
+        self,
+        idx: (
+            MaskType | StrLike | _IndexSliceTuple | list[ScalarT] | IndexingInt | slice
+        ),
+        value: (
+            Scalar
+            | NAType
+            | NaTType
+            | ArrayLike
+            | IndexOpsMixin
+            | Sequence[Scalar]
+            | DataFrame
+            | list
+            | Mapping[Hashable, Scalar | NAType | NaTType]
+            | None
+        ),
+    ) -> None: ...
+    @overload
+    def __setitem__(
+        self,
+        idx: tuple[_IndexSliceTuple, Hashable],
+        value: (
+            Scalar
+            | NAType
+            | NaTType
+            | ArrayLike
+            | IndexOpsMixin
+            | Sequence[Scalar]
+            | dict
+            | None
+        ),
+    ) -> None: ...
+    # Extra cases not supported by  `_LocIndexerFrame.__setitem__` /
+    # `_iLocIndexerFrame.__setitem__`.
+    @overload
+    def __setitem__(
+        self,
+        idx: IndexOpsMixin | DataFrame,
+        value: Scalar | NAType | NaTType | ArrayLike | Series | list | dict | None,
+    ): ...
     @overload
     def query(
         self,
@@ -1917,7 +1990,11 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
         **kwargs: Any,
     ) -> Series[_bool]: ...
     @final
-    def asof(self, where, subset: _str | list[_str] | None = None) -> Self: ...
+    def asof(
+        self,
+        where: Scalar | AnyArrayLike | Sequence[Scalar],
+        subset: Hashable | list[Hashable] | None = None,
+    ) -> Self: ...
     @final
     def asfreq(
         self,
@@ -2454,7 +2531,9 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
         **kwargs: Any,
     ) -> Series: ...
     # Not actually positional, but used to handle removal of deprecated
-    def set_axis(self, labels, *, axis: Axis = ..., copy: _bool = ...) -> Self: ...
+    def set_axis(
+        self, labels: AxesData, *, axis: Axis = 0, copy: _bool = ...
+    ) -> Self: ...
     def skew(
         self,
         axis: Axis | None = ...,
diff --git a/pandas-stubs/core/indexing.pyi b/pandas-stubs/core/indexing.pyi
index 832e2618a..868d10afc 100644
--- a/pandas-stubs/core/indexing.pyi
+++ b/pandas-stubs/core/indexing.pyi
@@ -3,7 +3,7 @@ from typing import (
     TypeVar,
 )
 
-from pandas.core.indexes.api import Index
+from pandas.core.base import IndexOpsMixin
 
 from pandas._libs.indexing import _NDFrameIndexerBase
 from pandas._typing import (
@@ -13,7 +13,7 @@ from pandas._typing import (
 )
 
 _IndexSliceTuple: TypeAlias = tuple[
-    Index | MaskType | Scalar | list[ScalarT] | slice | tuple[Scalar, ...], ...
+    IndexOpsMixin | MaskType | Scalar | list[ScalarT] | slice | tuple[Scalar, ...], ...
 ]
 
 _IndexSliceUnion: TypeAlias = slice | _IndexSliceTuple
diff --git a/pandas-stubs/core/series.pyi b/pandas-stubs/core/series.pyi
index 61eb0222e..321b82281 100644
--- a/pandas-stubs/core/series.pyi
+++ b/pandas-stubs/core/series.pyi
@@ -557,14 +557,14 @@ class Series(IndexOpsMixin[S1], ElementOpsMixin[S1], NDFrame):
     @final
     def __getattr__(self, name: _str) -> S1: ...
 
-    # Keep in sync with `iLocIndexerSeries.__getitem__`
+    # Keep in sync with `_iLocIndexerSeries.__getitem__`
     @overload
     def __getitem__(self, idx: IndexingInt) -> S1: ...
     @overload
     def __getitem__(
         self, idx: Index | Series | slice | np_ndarray_anyint
     ) -> Series[S1]: ...
-    # Keep in sync with `LocIndexerSeries.__getitem__`
+    # Keep in sync with `_LocIndexerSeries.__getitem__`
     @overload
     def __getitem__(  # type: ignore[overload-overlap] # pyright: ignore[reportOverlappingOverload]
         self,
@@ -1546,8 +1546,8 @@ class Series(IndexOpsMixin[S1], ElementOpsMixin[S1], NDFrame):
     @final
     def asof(
         self,
-        where: Scalar | Sequence[Scalar],
-        subset: _str | Sequence[_str] | None = None,
+        where: Scalar | AnyArrayLike | Sequence[Scalar],
+        subset: None = None,
     ) -> Scalar | Series[S1]: ...
     @overload
     def clip(  # pyright: ignore[reportOverlappingOverload]
diff --git a/tests/test_frame.py b/tests/test_frame.py
index eb2960b0f..63fa9e65e 100644
--- a/tests/test_frame.py
+++ b/tests/test_frame.py
@@ -292,6 +292,9 @@ def test_types_setitem() -> None:
     df[5] = [5, 6]
     df[["col1", "col2"]] = [[1, 2], [3, 4]]
     df[s] = [5, 6]
+    df.loc[:, s] = [5, 6]
+    df["col1"] = [5, 6]
+    df[df["col1"] > 1] = [5, 6, 7]
     df[a] = [[1, 2], [3, 4]]
     df[i] = [8, 9]