Acute protein phosphatase inhibition using 1 μM okadaic acid, a PP1 specific inhibitor [61], 30 min prior to a single dose of irradiation (10 Gy) allowed for the recovery of both pChek1-S345 and pP53-S15 levels in AEP-deficient MDA-MB-231 cells (Fig. 4F), strengthening the idea that AEP functions as a regulator of pChek1 and pP53 through the regulation of protein phosphatase activity in cancer cells, through the regulation of PPP1R10 levels. Here, PPP1R10 is linked to cancer.