This phenotype was clearly distinct from that of the three benign kidney tumors (one cystic nephroma and two mesoblastic nephromas) studied, in which non-hematopoietic (benign) tumor cells were negative for both CD45 and CD56, while they co-expressed HLA-DR, CD10, and EpCAM. This evidence concerns the gene NCAM1 and Cystic Nephroma.