In vivo, a significant increase in apoptotic nuclei is apparent in xenograft tumors harvested within 24 h after a 5-day course of Tasidotin. Mice treated with 100 mg/kg have a mean weight loss of >20% with no return to their baseline starting weight, and one mouse dies before the second treatment course. The mice treated with 90 mg/kg/d Tasidotin have a mean weight loss of <16% following each 5-day treatment of Tasidotin[2].