Of note, IC or bFGF are required to observe extracellular-Tat activity either in, in vitro or in vivo models of AIDS-KS, including endothelial and KS cell proliferation, migration, invasion, matrix-metalloproteases expression, and angiogenesis [13,24,44,45,46,47,48]. This evidence concerns the gene TAT and Kaposi's sarcoma.