Other proteins, such as HOOK1, TYMP, TEX12, FBN1, CLDN18, THY1, MUC5AC, CST6, WFDC2, PIK3IP1, and SERPINA4, were predominantly expressed in LGD or invasive IPMN but not in other groups (Fig. 8, Additional file 1: Fig. S7). The gene discussed is SERPINA4; the disease is pancreatic intraductal papillary-mucinous neoplasm.