These pathways lead to the constitutive activation of numerous transcription factors including nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB), NFAT, CRE, activator protein 1 (AP1) and hypoxia-inducible factor 1α (HIF-1α) in different cell lines [e.g., COS-7, HEK293, T cells, and monocytes, but also more relevant cells such as KSHV-positive primary B cells derived from KS patients (Azzi et al., 2013), the KS-derived endothelial cell line KSIMM, primary endothelial cells (Pati et al., 2001), and PEL cells (Cannon and Cesarman, 2004)]. Here, HIF1A is linked to Kaposi's sarcoma.