NOD1 and cancer: Colocalization inside cancer cell PaCS of H. pylori virulence factors like VacA, CagA, urease or outer membrane proteins, the H. pylori receptor NOD1, polyubiquitinated proteins, and, occasionally, of H. pylori itself, nicely reproduce the ultrastructural and cytochemical patterns of such structures as already detailed in non-neoplastic gastric epithelium and in epithelial cell lines incubated with H. pylori culture filtrate.