Inhibition of STAT5 activity was also reported for Indirubin derivatives, including E804, which blocked STAT5 phosphorylation and STAT5 DNA-binding activity in CML cells [151], associated with downregulation of MCL-1 and BCL2L1 expression. The gene discussed is STAT5B; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.