On the one hand, the c-KIT endothelial positivity suggests a reversion of the tumor cells to fetal endothelial cell phenotype similar to angiosarcomas [6], [11], [15] and can sustain the origin of KS in the precursor circulating the pluripotent endothelial cells and also the possible endothelial-mesenchymal transition. This evidence concerns the gene KIT and Kaposi's sarcoma.