RRM1 and severe congenital neutropenia: RRM1 expression was also examined in different types of low-grade malignant pancreatic diseases such as intraductal papillary mucinous neoplasia (IPMN) with low and intermediate-grade dysplasia, serous cyst neoplasia (SCN), and mucinous cyst neoplasia (MCN) (Figs 1C and S1).