CCNA2 and cytomegalovirus infection: Therefore, to gain further insights into HCMV-induced SAMHD1 phosphorylation, we next asked whether Cdk1/2 were involved in T592 phosphorylation in response to HCMV infection, since cellular cyclin A2/Cdk1/2 complexes have been shown to phosphorylate SAMHD1 at T592 [35–42].