RBM15 and acute megakaryoblastic leukemia: RBM15-MKL1, also known as OTT-MAL, is a chimeric fusion protein first discovered in 2001 in t(1;22)(p13;q13) rearranged cases of acute megakaryoblastic leukemia (AMKL) [201,202] and was overall found to be mainly associated with pediatric de novo AMKL, which accounts for two thirds of AMKL in children [203].