A molecule widely believed to fight many forms of cancer actually helps deadly thyroid tumors grow, and cancer therapies now being tested in humans might boost the activity of this newly revealed bad guy, researchers at Mayo Clinic in Florida say. Their findings are published online this month in the Journal of Cell Science. The study found that in anaplastic thyroid cancer, the Forkhead transcription factor, FOXO3a, is not the helpful tumor suppressor everyone thought it was, but, instead, is a lethal promoter of tumor growth. When FOXO3a was silenced in laboratory models of human anaplastic thyroid cancer, the cells...