May play a role in growth regulation. Is associated with G2/M phase arrest in response to DNA damage. May be an intermediate by which p53 mediates its role as an inhibitor of cellular proliferation. Binds to B' regulatory B subunits of protein phosphatase A (PP2A) following induction by p53 (in vitro). Highest levels in kidney, heart and skeletal muscle. Belongs to the cyclin family. Cyclin G subfamily.