In chronic myeloid leukemia (CML) and myeloproliferative diseases induced by TEL-JAK2, STAT5 is activated by a variety of hematopoietic and non-hematopoietic cytokines and growth factors to promote the development of these tumors (Lin et al., 2000; Levis et al., 2002; Subramaniam et al., 2020). The gene discussed is STAT5B; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.