Cyclin-G1 (CCNG1) belongs to the cyclin family and contains the cyclin box. CCNG1 may have a part in growth regulation and is associated with G2/M phase arrest in response to DNA damage. CCNG1 may be an intermediate by which p53 mediates its role as an inhibitor of cellular proliferation. The CCNG1 protein lacks the protein destabilizing (PEST) sequence which is present in other family members.