Acriflavine (Acriflavinium chloride 3,6-Acridinediamine mix) is a papain-like protease (PL(pro)) inhibitor, a fluorescent dye for labeling high molecular weight RNAs, has antimicrobial and anticancer activity, inhibits SARS-CoV-2 and other beta-coronaviruses, and can be used for research on leukemia. be used to study leukemia.