However, opposite trends have been observed in certain cancers, such as pancreatic ductal adenocarcinoma, where patients with low tumor‐infiltrating CD161+CD8+ T cells exhibited the worst survival.[12a] This highlights a tumor‐type‐specific role of CD161, likely influenced by the distinct TME and the dynamic balance between activation and exhaustion of CD161+CD8+ T cells. Here, KLRB1 is linked to pancreatic ductal adenocarcinoma.