CD274 and growth hormone-producing pituitary gland neoplasm: In our previous study, it was demonstrated that the gut microbiota of patients with somatotropinoma can affect the immune indexes of tumor mouse models, which is that intestinal microbes from patients with somatotropinoma promoted the growth of subcutaneous tumors in mice and up-regulated the number of programmed cell death-ligand 1 (PD-L1) positive cells in tumor tissue (8).