[15]  Thiopurine analogue inhibitors of severe acute respiratory syndrome-coronavirus papain-like protease, a deubiquitinating and deISGylating enzyme  Chen et al  Taiwan  2009  6-mercaptopurine (6MP) and 6-thioguanine (6TG) have been used in cancer chemotherapy for treatment of acute lymphoblastic or myeloblastic leukaemia and were found to be specific inhibitors for the SARS coronavirus.