The PD-L1 expression in our patients and in the study by Bahr et al. was negligible [35]; however, as demonstrated by Ozdirk et al. in a small series of neuroendocrine neoplasms of different origin but also in other histological types, patients with negative or low PD-L1 expression on tumor cells may still derive some clinical benefit from anti-PD-L1 treatment [34,36]. This evidence concerns the gene CD274 and neoplasm.