STAT3 and STAT5 are aberrantly tyrosine‐phosphorylated in cancer cells and are crucial effectors of different tyrosine kinase oncogenes (TKO) such as FLT3‐ITD in acute myeloid leukaemia (AML) and BCR‐ABL in CML.25, 26. Here, ABL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.