CDKN1A and infection: Proviral DNA formation was also enhanced in cyclin D2 and p21 knockdown GM-CSF macrophages in short-term infections with the fully replicative HIV-1 R5-tropic strain BaL (roughly 3-fold increase, p = 0.007 for siCCND2 and p = 0.03 for siCDKN1A respectively, Fig 4E).