The notion that an increased activation of ATM promotes apoptosis induction by hydroxyurea in PDAC cells is in line with our recent finding that a genetic elimination of the phosphatase-2A subunit PR130 prevents the entinostat-induced dephosphorylation of ATM and that this sensitizes colorectal cancer cells to apoptosis induction by hydroxyurea plus entinostat. Here, PPP2R3A is linked to colorectal cancer.