SMAD4 and gastric cancer: A total of 949 genes have at least one somatic non-silent SNV or small INDEL in coding region (Supplementary Data 1), of which six significantly mutated genes (SMG) were identified, including TP53 (25%), CDH1 (15.6%), PIK3CA (12.5%), ERBB2 (6.3%), LCE1F (6.3%), and OR8J1 (6.3%) (Fig. 2 and Supplementary Data 2), but not the well-reported SMGs enriched in diffuse type, such as ARID1A, RHOA, and SMAD4 (Fig. 2, Supplementary Fig. 7, and Supplementary Data 2), indicating possible distinct genomic features of SRCC from other diffuse type of gastric cancer.