CD19 and acute lymphoblastic leukemia: Unsorted cells and three of four BCP‐ALL subpopulations (CD34+/CD19+, CD34+/CD19− and CD34−/CD19+) responded to both inhibitors, with viability reduced to 1·6 ± 1·6% using 1 μmol/l navitoclax (IC50 range 18–54 nmol/l) and 2·4 ± 1·6% with venetoclax (IC50 range 3–120 nmol/l).