BCR and acute lymphoblastic leukemia: For example, only 75% of T-cell acute lymphoblastic leukemia (T-ALL) patients achieve remission (3), and patients with the B-cell acute lymphoblastic leukemia (B-ALL) subtypes of BCR-ABL1, BCR-ABL1 like, and KMT2A (MLL) rearranged have a high risk of treatment failure and poor prognosis (4–7).