CCNA1 May be involved in the control of the cell cycle at the G1/S (start) and G2/M (mitosis) transitions. May primarily function in the control of the germline meiotic cell cycle and additionally in the control of mitotic cell cycle in some somatic cells. Belongs to the cyclin family;CCNA2 a member of the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle.