CD274 and pancreatic neoplasm: Patients who received the GVAX vaccine 2 weeks prior to surgical resection had an increased frequency of tumors positive for PD‐L1 (12.5% of resected tumors in the unvaccinated group vs 25% of resected tumors in the GVAX group), suggesting this as a likely mechanism of immune resistance.32 Building on these results, GVAX is currently being studied in a clinical trial with or without nivolumab for patients with resectable pancreatic cancer at Johns Hopkins University (NCT02451982; clinicaltrials.gov).