There is a renewed interest in the ultimate role of fatty acid synthase ( FASN) a key lipogenic enzyme catalysing the terminal steps in the de novo biogenesis of fatty acids - in cancer pathogenesis. Tumour- associated FASN, by conferring growth and survival advantages rather than functioning as an anabolic energy- storage pathway, appears to necessarily accompany the natural history of most human cancers. A recent identification of cross- talk between FASN and well- established cancer- controlling networks begins to delineate the oncogenic nature of FASN- driven lipogenesis. FASN, a nearly- universal druggable target in many human carcinomas and their precursor lesions, offers new therapeutic opportunities for metabolically treating and preventing cancer.