As shown in figure 1a and b, both PC3/Luc and DU145 cells were specifically stained by NKp30-Ig and NKp46D2-Ig, but not by the control CD99-Ig (grey histograms), thus indicating the expression of ligands for these two NK activating receptors on prostate tumor cell lines. This evidence concerns the gene CD99 and prostate neoplasm.