KLRB1 and pancreatic ductal adenocarcinoma: Existing studies have shown that KLRB1 is associated with various types of tumors, and CD161 has become one of the hot spots of research into immunotherapy targets in recent years, in the malignant tissues of testicular germ cell tumors (TGCTs) [10], pancreatic ductal adenocarcinoma [11], HPV-positive oropharyngeal cancer [12], and diabetic non-small cell lung cancer [13].