CD274 and neuroendocrine carcinoma: We found that about 29% of acinar PCs, 7% of ductal PCs, and 46% of neuroendocrine carcinomas/tumors were PD-L1+ by immunohistochemistry, despite some variations in the positivity rate of different antibody clones, as well as potential limitations due to pre-analytical factors and inter-observer interpretation variability.