MEN1 and carcinoid tumor: Other factors may emerge that specifically identify subpopulations at an enhanced risk of developing PPI-associated carcinoids including: presence of chronic gastritis (short of corpus atrophy) due to autoimmunity or H. pylori infection—the latter perhaps accelerated by PPI therapy [22,42,43]; the dose or duration of PPI therapy; the presence of a PPI slow-metabolizer phenotype; or the presence of mutations in other genes e.g., MEN-1 or those affecting somatostatin responses.