In practice, loss-of-function CDH1 variants are more commonly associated with hereditary diffuse gastric cancer (HDGC) syndrome6,7, which occurs both with and without concomitant ILC; to delineate between the two syndromes, families with a history of ILC and no history of diffuse gastric cancer are typically referred to as having hereditary lobular breast cancer (HLBC) specifically5,8,9. This evidence concerns the gene CDH1 and Familial gastric cancer.