[摘要]:More information is needed about genetic factors that initiate development of pancreatic intraepithelial neoplasms-the most common precursors of pancreatic ductal adenocarcinoma. We show that more than 99% of the earliest-stage, lowest-grade, pancreatic intraepithelial neoplasm-1 lesions contain mutations in KRAS, p16/CDKN2A, GNAS, or BRAF. These findings could improve our understanding of the development and progression of these premalignant lesions.