Co-culture of peripheral blood lymphocytes with pancreatic cancer organoids resulted in significantly increased induction of tumour reactivity in T cells compared to healthy controls, as assessed by intracellular staining of granzyme B. Staining for expression of the activation marker CD137 showed that the T cell responses induced by co-culture were specific to the cancer organoids. The gene discussed is GZMB; the disease is familial pancreatic carcinoma.