BRD4 and neoplasm: (+) -JQ1 can reduce the expression of histone lysine methyltransferase G9a by epigenetic way, thereby inhibiting Bromodomain-containing protein 4 (BRD4), a tumor-driven bromodomain protein that is often highly expressed in tumors, to regulate ferritin phagocytosis, iron accumulation and reactive oxygen species production (Sui et al., 2019).