This is in agreement with a previous study on mice with subcutaneous human prostate tumours, where the tumourigenic effect of orlistat treatment, at the same daily dose as in our study, was not accompanied by body weight loss.31 In contrast, the FASN inhibitors cerulenin and C75, are known to lead to severe decrease in food intake and induction of weight loss in mice.32, 33, 34 Hence, orlistat appears to be a preferable FASN inhibitor in tumours, as it does not cause weight loss, which would be a significant limiting factor in often cachectic cancer patients. This evidence concerns the gene FASN and cancer.