KRAS and pancreatic ductal adenocarcinoma: Considering that more than 90% of patients with pancreatic ductal adenocarcinoma (PDAC) have KRAS mutations, especially KRAS G12D (41%), G12V (34%), and G12R (16%) mutations (3), TILs or peripheral blood lymphocytes from patients with PDAC may represent ideal sources for screening T cells targeting KRAS mutations, given that these patients may have already mounted an endogenous response against their KRAS mutation.