Fatty acid synthase (FAS)-dependent endogenous fatty acid synthetic activity has been found to be abnormally elevated in a subset of aggressive breast carcinomas [30], in particular ERBB2-overexpressing tumors [31], whereas here, high expression of many genes involved in fatty acid/lipid metabolism and degradation were coupled to the luminal A phenotype, know to be associated with a relatively good prognosis [10]. This evidence concerns the gene FAS and breast carcinoma.