The addition of a mixture of anti-Notch1, anti-Notch2, anti-Notch3 and anti-Notch4 (pan-R-abs) or specific Anti-Notch blocking antibodies alone, significantly enhanced drug sensitivity of AML cells in co-culture with hBM-MSC* (Figures 7C, S6). The gene discussed is NOTCH4; the disease is acute myeloid leukemia.