Considering the fact that KS tumors have been associated with numerous cytokines, chemokines and diffusible factors in their microenvironments [78], [79], [80], [81], it is highly likely that multiple KS-associated viral and/or cellular factors may activate the gp130/Akt pathway to prime the initial activation of PROX1 transcription [59]. Here, PROX1 is linked to Kaposi's sarcoma.