Bcl-2 is a bona fide direct target of STAT5 so that STAT5 requires the N-domain for the suppression of miR15/16, induction of Bcl-2, and induction of survival signaling in mast cells and myeloproliferative neoplasms (MPNs) [46, 47]. Here, STAT5B is linked to myeloproliferative neoplasm.