We found that the transcription factor Ets-1 is highly expressed in KS spindle cells and is upregulated during KSHV infection of endothelial cells in culture.
The authors show by in situ hybridization that c-ets1 is transcribed in the endothelia during angiogenesis in human embryos, in granulation tissue, and especially during tumor vascularization. c-ets1 mRNAs were also detected in the fibrocytes of tumor stroma and in the spindle cells of Kaposi's sarcomas, regarded as cells of endothelial origin.