APOBEC3B and digestive system neuroendocrine tumor, grade 1/2: These findings agree with previous studies in breast [49] and ovarian carcinomas [50], esophageal squamous cell carcinomas [51], and gastroenteropancreatic neuroendocrine tumors [52], where a rabbit polyclonal antibody that recognizes an epitope of 14 amino acids near the N-terminal of A3B was used, as well as with our previous work in HNSCC samples, where a rabbit polyclonal antibody raised against residues 1–100 of the human A3B protein was applied.