USP7 and cancer: This finding offers a crucial point to elucidate the role of GRA16 as a HAUSP inhibitor, that is, GRA16 plays a role in the interaction between PTEN and p53 in the process from HASUP inhibition to p53 stabilization, and as a precondition for that role, the presence of undamaged p53 is necessary for the apoptosis of cancer cells by the role of GRA16.