JAK3 and acute lymphoblastic leukemia: Thus, childhood ETP-ALL presents cytokine-activating somatic mutations and mutations in genes involved in the RAS signaling pathway (e.g., NRAS, KRAS, FLT3, IL7R, JAK3, JAK1, SH2B3, and BRAF), genetic alterations that inactivate genes involved in hematopoietic development (e.g., GATA3, ETV6, RUNX1, IKZF1, and EP300), and mutations in histone modifier genes (e.g., EZH2, EED, SUZ12, SETD2, and EP300).