The risk factors for developing a P-NET are body mass index, smoking, alcohol consumption, genetic factors (-1031 TC and CC genotype distribution of TNF-α promoter polymorphism and IL1β-511 for single-nucleotide polymorphism), family history of cancer (especially of P-NET) and first-degree family-history of esophageal cancer, adding to the risk factors other types of cancer, like gallbladder, gastric or ovarian cancer and sarcoma and personal history of chronic pancreatitis [31,32,33,34,35,36,37,38]. This evidence concerns the gene TNF and ovarian cancer.