PF4 and Thrombocytopenia: The consistent downregulation of GATA1, NFE2, and PF4 transcription within hours post-BMS-986158 treatment in both preclinical and clinical studies demonstrates that BET inhibitors induce thrombocytopenia by altering GATA1 gene expression and its downstream genes, NFE2 and PF4, which regulate megakaryopoiesis and thrombopoiesis.