JAK2 and acute myeloid leukemia: Notably, hyperactivation of RAS/RAF/MAPK and STAT5 signaling has also been detected in other myeloid neoplasms, such as non-CML chronic myeloproliferative disorders correlating with JAK2 V617F mutation [70] and Flt3-ITD-positive AML [71], and in all cases it was correlated with the resistant phenotype and overall poor prognosis and survival [64].