The gene most frequently associated with hereditary cases is CDH1 (OMIM *192090) [6], pathogenic variants of which are causative of the hereditary diffuse gastric cancer syndrome (HDGC, OMIM #137215), a dominant condition predisposing to both DGC and breast cancer of lobular histotype (LBC). Here, CDH1 is linked to CDH1-related diffuse gastric and lobular breast cancer syndrome.