CDK2 and HIV-1 infection: As phosphorylation of the retroviral restriction factor SAMHD1 (i. e. its inactivation) by CDK2 is associated with the exit of the quiescent state and also because this molecular event controls T-cell susceptibility to HIV-1 infection [13], we also measured pSAMHD1 levels after AS1842856 treatment of PBT.