RNF43 and Pancreatic cysts: Approximately 5–7% of PDAC and 15–40% of premalignant IPMNs and MCNs harbor mutations in RNF43. Comparatively infrequent in PanIN and PanIN-associated PDAC, RNF43 mutations are primarily linked to the malignant progression in IPMN and MCN (Furukawa et al., 2011; Wu et al., 2011; Jiang et al., 2013; Waddell et al., 2015; Bailey et al., 2016; Cancer Genome Atlas Research Network [CGARN], 2017) and are useful ancillary markers in pancreas cyst fluid diagnostics (Springer et al., 2015).