NAPA and infection: Although H. pylori virulence determinants CagA and VacA exert the most prominent cellular changes and damage during the infection, H. pylori factors such as lipopolysaccharide (LPS), ADP-heptose, peptidoglycan (PGN), cholesterol glucosides, neutrophil activating protein A (NapA), γ-glutamyl transferase (GGT), urease, serine protease HtrA, and a repertoire of adhesion proteins are also playing important roles in the colonization, adhesion, survival and chronicity of infection [12,13].