SMAD4 and cancer: These results indicate that mutations in KRAS, TP53, SMAD4, and CDKN2A, the four well-known genes frequently mutated in PDACs, were also prevalent in the current cohort at a rate almost coinciding with published reports8,9, although some mutations, i.e., TP53Q104fs (c.311_318del), SMAD4H105fs (c.316dupA), and SMAD4V409fs (c.1227_1228del), seemed to be novel, as they were unreported in the Catalogue of Somatic Mutations in Cancer (COSMIC; http://cancer.sanger.ac.uk/cosmic) database.