Moreover, our recent studies showing that PDGFRA signaling is an oncogenic driver in KSHV sarcomagenesis and that it is consistently found in AIDS-KS tissue samples in its activated form [14], point to a bone marrow-derived PDGFRA(+) MSCs such as the Pα(+)S MSCs, which our study now show is a cell progenitor target of KSHV-driven sarcomagenesis. This evidence concerns the gene PDGFRA and Kaposi's sarcoma.