Furthermore, the safety and therapeutic effects of these diterpenes are also suggested by the prolonged survival of SCID mice transplanted with wild-type or T315I BCR/ABL cells (50% of mice were alive after 25 weeks of treatment while untreated leukaemic mice died within 5 weeks), and by the lack of signs of toxicity or leukaemia after administration of these compound for 18 (Neviani et al, 2005) and 25 (our unpublished data) weeks at 4 and 8 mg kg−1 week−1. The gene discussed is ABL1; the disease is leukemia.