In this study, we investigated the frequency and extent of neuroendocrine differentiation, identified by synaptophysin expression, in a large cohort of 1013 colorectal carcinomas (1002 “conventional” adenocarcinomas with a non-neuroendocrine morphology on H&E sections and 11 colorectal MANECs) and correlated it with clinicopathological features and survival. The gene discussed is SYP; the disease is medical procedure.