Recent studies have reported that the expression of vFLIP and vGPCR in both PEL cell lines (BC-1, BC-3, and BCBL-1) and primary B cells derived from KS patients is critical for chronic NF-κB activation and survival of PEL cells [14, 16, 64, 65]. The gene discussed is NFKB1; the disease is Kaposi's sarcoma.