PTPA and neoplasm: Thus, PP2A may also be involved in tumor immunity by regulating macrophage localization and function in tumors.[33] Additionally, PP2A‐SET interactions have been found to induce granzyme B expression and modulate human natural killer (NK) cell cytotoxicity.[34] Although PP2A can participate in regulatory roles in various cellular subpopulations, its subunits, including PP2Ac, have received little attention in OA, particularly in osteoclast studies.