FASN and obesity due to melanocortin 4 receptor deficiency: Pancreatic cancer (PC) is extremely malignant, and the overall 5‐year survival rate is less than 10%, this disease has surpassed breast cancer as the third leading cause of cancer‐related death, according to the latest data from the American Cancer Society.[1, 2, 3, 4] Obesity is a global pandemic that has been associated with the development of PC.[5, 6] An increasing number of studies have shown that obesity‐related genes, such as fatty acid synthase and G protein‐coupled receptors, play important roles in regulating the occurrence and development of PC.[7, 8]