JAK1 and acute lymphoblastic leukemia: On the other hand, WGS has shown that 81% of pediatric ETP-ALL cases harbor mutations in genes regulating hematopoietic development (i.e., GATA3, RUNX1, ETV6, IKZF1, and EP300), in cytokine receptors and members of the RAS signaling pathway (i.e., BRAF, FLT3, IGFR1, JAK1, JAK3, KRAS, and NRAS), and in components of the polycomb repressor complex 2 (PRC2) (i.e., EED, EZH2, and/or SUZ12) [30].