BCR and chronic myelogenous leukemia, BCR-ABL1 positive: The incubation of CML cell lines in atmosphere at 0.1% O2 was paralleled by a time-dependent suppression of BCR/Abl protein, which did not occur in cells incubated at 21% O2 (Figures 1(a) and 1(b)), in keeping with what was previously shown [33, 35, 40].