Analyzing a total of 146 separate primary tumors from 28 patients, we comparatively assessed proliferative activity/tumor grade (WHO-grade), expression of basal diagnostic markers (synaptophysin, chromogranin A, CDX2, and serotonin), and SSTR2a status as well as the contexture of the immunogenic microenvironment (T-/B-cell density and PD-L1 expression) between the separate tumors. The gene discussed is CD274; the disease is neoplasm.