蛋白质家族中的physin家族，包括突触素（SYP）、类突触素1（SYPL1）、类突触素2（SYPL2）和突触铁蛋白（SYNRP），是四次跨膜转运泡蛋白，分布于消化系统中。其中，SYP是神经内分泌肿瘤（NENs）组织病理学鉴定的必需标志物，尤其是在胃肠胰NENs（GEP-NENs）中。最近，血液中的SYP，即血小板和循环肿瘤细胞上的SYP，已经与GEP-NENs的临床病理学特征相关，并可能具有预后意义。血清中的SYPL1也代表着具有前景的结直肠癌生物标志物。本章介绍了physin结构的概述以及其作为消化道肿瘤的诊断、预后和治疗工具的潜在用途。版权所有©2022 Elsevier Inc.。

The physin family of proteins, synaptophysin (SYP), synaptophysin like 1 (SYPL1), synaptophysin like 2 (SYPL2) and synaptoporin (SYNRP), are tetratransmembrane transport vesicle proteins distributed throughout the digestive system. Of these, SYP is a required marker for histopathologic identification of neuroendocrine neoplasms (NENs), especially in gastroenteropancreatic NENs (GEP-NENs). Recently, bloodstream SYP, i.e., on platelets and circulating tumor cells, has been correlated to clinicopathologic features of GEP-NENs and may have prognostic significance. Serum SYPL1 also represents a promising biomarker for colorectal cancer. This chapter provides an overview of physin structures and potential use as diagnostic, prognostic and therapeutic tools for digestive tract neoplasms.Copyright © 2022 Elsevier Inc. All rights reserved.