CTLA4 and gastric cancer: In recent years, with the increasing use of ICIs in the field of esophageal and gastric cancer, the likelihood of encountering an incidental NEC case like this one may increase. Clinical trials of ICIs for neuroendocrine neoplasms (NEN) are also underway. In this regard, the phase II basket trial of dual anti-CTLA-4 and anti-PD-1 blockade in rare tumors (DART SWOG 1609) reported that the combination of ipilimumab and nivolumab was well tolerated in patients with high-grade, regardless of the primary site, with an overall response rate (ORR) of 42% [18].