STAT5B and cancer: Since 2013, somatic STAT5B mutations were discovered in large granula lymphocytic leukemia (LGL) [44], in T-promyelocytic leukemia (T-PLL) [45], in acute T-cell leukemia (T-ALL) [46,47] and hepatosplenic T-cell lymphoma (HSTL) [48], where more mutations can be expected through progress in the cancer genome project [200].