Apart from diffuse gastric and lobular breast carcinomas where germline mutations and somatic inactivation of the E‐cadherin (CDH1) locus occurs (Berx et al., 1996; Fitzgerald and Caldas, 2004; Guilford et al., 1998; Peinado et al., 2004), different studies have supported E‐cadherin detection as a diagnostic marker in several tumor types. The gene discussed is CDH1; the disease is breast carcinoma.