Earlier, overexpression experiments have suggested that CD44 may exert a tumour-suppressive function (Gao et al, 1998), although other studies have implicated CD44 in CaP cell proliferation, adhesion, migration and invasion in vitro, as well as in metastatic dissemination in vivo (Paradis et al, 1998; Omara-Opyene et al, 2004). This evidence concerns the gene CD44 and neoplasm.