Homozygous carriers of the stop codon (FUT2 rs601338 AA carriers corresponding to FUT2 rs602662 AA carriers) are nonsecretors and they have been shown to be resistant to infections with Helicobacter pylori [27, 28] and Norovirus, the major cause of viral acute gastroenteritis worldwide [29–32]. The gene discussed is FUT2; the disease is infection.