↑ AMP production in pancreatic cells resulted in a macrophage switch from an inflammatory (M1) to a regulatory (M2) phenotype and T-reg cells; ↓ AMP secretion in the gastroenteric tract seemed to induce bacterial overgrowth and dysbiosis in the gut and pancreatic cancer development by increasing myeloid-derived suppressor cell infiltration and by reducing antitumor cytotoxic CD8+ T cells. Here, CD8A is linked to familial pancreatic carcinoma.