In early stages, poorly cohesive carcinomas can display 3 histogenetic pathways, with particular molecular behaviors: “carcinoma with intraepithelial pagetoid onset” (with or without a switch from E-cadherin to SLUG positivity), “carcinoma with early lymphatic invasion” (carcinoma limited to mucosa but with carcinomatosis of the lymph vessels from subjacent layers), and “microglandular-type poorly cohesive carcinoma” (the onset is similar with adenocarcinoma but abrupt dedifferentiation can be seen in the submucosa, with persistence of a dual component in the deep layers). The gene discussed is CDH1; the disease is carcinoma.