Several FZD receptors are highly expressed in CML CD34+ cells, and FZD4 silencing inhibits the growth of these cells and sensitizes them to TKI treatment, even in the absence of MSCs, implying that CML CD34+ cells may secrete WNT ligands [43]. The gene discussed is FZD4; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.