Acts as an inhibitor of serine/threonine-protein phosphatase 2A (PP2A) activity. Potentiates ubiquitin-mediated proteasomal degradation of serine/threonine-protein phosphatase 2A catalytic subunit alpha (PPP2CA). Inhibits PP2A-mediated dephosphorylation of WEE1, promoting ubiquitin-mediated proteolysis of WEE1, thereby releasing G2/M checkpoint. Belongs to the FAM122 family.