MEF2C and acute lymphoblastic leukemia: ETP-ALL immunophenotype was associated with high levels of BAALC (P = 0.003), MEF2C (P = 0.003), LYL1 (P = 0.01), LYN (P = 0.01), XIST (P = 0.02), and lower levels of ST20 (P = 0.007) and EML4 (P = 0.03).