NCAM1 and neoplasm: Preliminary evidence for the existence of a tumour stem/progenitor population in classical tri-phasic human WT comes from our in vitro work with low-passage WT cultures derived from primary tumours showing after immunophenotyping that a sorted NCAM+ cell fraction is highly clonogenic and enriching for a renal stemness signature set predicted by previous WT microarray experiments (Dekel et al, 2006; Metsuyanim et al, 2008; Pode-Shakked et al, 2009).