Since several Wnt family members have been reported in BM stromal cells, it is possible that leukaemia cells respond to different proteins of the Wnt/beta-catenin pathway secreted by stromal cells in a paracrine fashion (Austin et al, 1997; Van Den Berg et al, 1998; Etheridge et al, 2004). The gene discussed is CTNNB1; the disease is leukemia.