As such, in pancreatic cancer, CAFs have been reported to increase the expression of PD-1, cytotoxic lymphocyte-associated antigen-4 (CTLA-4), lymphocyte-activation gene-3 (LAG-3), and T cell immunoglobulin and mucin-domain containing-3 (TIM-3), on both CD4+ and CD8+ T cell [195]. Here, PDCD1 is linked to familial pancreatic carcinoma.