To address the role of p21 for efficient viral lytic replication in a biologically relevant KSHV-infection system, we chose to use two PEL cell lines, TPA-treated BC-3 and TREx BCBL1-Rta (here referred to as BCBL1RTA) cells that can be induced to lytic replication through doxycycline-inducible expression of RTA [54]. This evidence concerns the gene CDKN1A and infection.