PTPA and ovarian carcinoma: Recently, it was shown that the serine/threonine phosphatase PP2A can stabilize Rb2/p130 by dephosphorylation at serine 1080 and threonine 1097 in human ovarian carcinoma cells [20] by mediating nuclear import of the protein; acetylation of a lysine residue within this nuclear localization sequence might have a role in this stabilization process.