– STAT5-IN-3 (Compound 14a) is a STAT5 inhibitor with anticancer properties. It works by blocking the tyrosine phosphorylation of STAT5A/5B at the Y694/699 sites, significantly reducing the expression of the STAT5B protein. This leads to the inhibition of downstream gene transcription, thereby preventing the proliferation and survival of leukemia cells. Additionally, STAT5-IN-3 has significant potential in overcoming chemotherapy resistance.