ABCB1 and acute lymphoblastic leukemia: El-Osta et al. aimed at elucidating the underlying mechanism of ABCB1 gene regulation in CCRF-CEM, a drug-sensitive T-cell acute lymphoblastic leukemia (T-ALL) cell line, and its subline CEM-A7R, established by selecting CCRF-CEM for resistance against doxorubicin [128,165].