Indeed, exposure of the murine pro-B cell line BA/F3 or the leukaemic cell lines THP1 (MLL-AF9+; AML) or K562 (BCR-ABL1+; chronic myeloid leukaemia (CML)), stably transfected with this construct, to increasing calcium concentrations enhanced GFP fluorescence (Supplementary Fig. 1b–g, Supplementary Table 1). Here, MLLT3 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.