FASN and obesity due to melanocortin 4 receptor deficiency: First, we investigated the cytotoxic potency of 3 inhibitors of FASN, the cerulenin derivative C75, the anti-obesity drug Orlistat, and TVB-3166, one of a series of structurally related FASN inhibitors that includes TVB-2640, the first-in-human FASN for cancer clinical trials.21