PDGFRA and Kaposi's sarcoma: Paradoxically, long term cultures of vGPCR-null mECK16 upregulated PDGFs and PDGFRA signaling showing that, as suggested by our results; PDGFRA is a critical survival pathway that should be compensated even in the absence of vGPCR signaling via a mechanism—whose elucidation lies outside the scope of the present paper—that could be critical in maintenance of human KS lesions which are mostly latently infected and not expressing vGPCR.