XPO1 and acute lymphoblastic leukemia: Gene rearrangements of AF10 generate diverse AF10 fusion proteins with many partners besides MLL, including CALM (also known as PICALM), DDX3X, NUP98, and XPO1 (also known as CRM1), causing multiple lineages of malignant leukemia, including acute myeloid (AML), B-cell acute lymphoblastic (B-ALL), and T-cell acute lymphoblastic leukemia (T-ALL)19–23.