GPR68 and pancreatic neuroendocrine neoplasm: If considering only the tumour entity with the highest percentage of GPR68-positive cases (pancreatic neuroendocrine neoplasms), a negative correlation was found between GPR68 expression and Ki-67 levels (rsp = -0.341, p = 0.020) or tumour grade (rsp = -0.269, p = 0.028), while a positive association between GPR68 and SST2 expression (rsp = 0.328, p = 0.024) was observed.