diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index b4a278185b01b..932805463d1c3 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -3558,16 +3558,16 @@ def T(self) -> DataFrame:
     # ----------------------------------------------------------------------
     # Indexing Methods
 
-    def _ixs(self, i: int, axis: int = 0):
+    def _ixs(self, i: int, axis: int = 0) -> Series:
         """
         Parameters
         ----------
         i : int
         axis : int
 
-        Notes
-        -----
-        If slice passed, the resulting data will be a view.
+        Returns
+        -------
+        Series
         """
         # irow
         if axis == 0:
diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index 589ea6e67d926..a10cfe1c615fa 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -2014,7 +2014,7 @@ def __getstate__(self) -> dict[str, Any]:
         }
 
     @final
-    def __setstate__(self, state):
+    def __setstate__(self, state) -> None:
         if isinstance(state, BlockManager):
             self._mgr = state
         elif isinstance(state, dict):
@@ -2047,7 +2047,7 @@ def __setstate__(self, state):
         elif len(state) == 2:
             raise NotImplementedError("Pre-0.12 pickles are no longer supported")
 
-        self._item_cache = {}
+        self._item_cache: dict[Hashable, Series] = {}
 
     # ----------------------------------------------------------------------
     # Rendering Methods
diff --git a/pandas/core/series.py b/pandas/core/series.py
index 6ebee74810305..06815348fe4b9 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -932,7 +932,7 @@ def _take_with_is_copy(self, indices, axis=0) -> Series:
         """
         return self.take(indices=indices, axis=axis)
 
-    def _ixs(self, i: int, axis: int = 0):
+    def _ixs(self, i: int, axis: int = 0) -> Any:
         """
         Return the i-th value or values in the Series by location.