DPYD and obesity due to melanocortin 4 receptor deficiency: In a recent in vivo study, Vanderveen et al., reported that obesity alters the metabolism of 5-fluorouracil (5FU), significantly reducing the survival in obese mice receiving the drug, reducing dihydropyridine dehydrogenase (DPD) activity, the enzyme responsible for 5FU metabolism and increase the inflammatory gene signature in peripheral tissues [32].