The existence of spindle-shaped cells within a KS lesion positive for phospho-PDGFRA and negative for KSHV LANA would exemplify a LANA-negative proliferative spindle cells which are not rare in KS, since KS lesions with varying levels of KSHV infected cells, ranging from <10% to >90% of the total cell population in the KS lesions have been reported [2, 4]. This evidence concerns the gene PDGFRA and Kaposi's sarcoma.