In murine AML, CML and B-cell acute lymphoblastic leukaemia (B-ALL), CaSR expression was highest on the respective putative leukaemic stem cells, i.e. lineage (Lin)− or granulocyte-monocyte progenitor (GMP) cells in MLL-AF9+ AML23, Lin− c-Kit+ Sca-1+ (LKS) CD150+ CD48− (SLAM) cells in CML24 and BP-1+ pre-B cells in B-ALL22 (Supplementary Fig. 3g–i). The gene discussed is MLLT3; the disease is precursor B-cell acute lymphoblastic leukemia.