PPP2R5C and neoplasm: Combined, these observations suggest that cancer-derived point mutations in Aβ may lead to loss of tumor suppressive activity due to severely crippled catalytic function (as in the case of R233C) or as a result of skewed phosphatase activity against only a subset of substrates, as shown previously in the case of mutants like P65S that can bind the catalytic subunit, but not the tumor suppressive regulatory subunits B56α and B56γ.