As such, elevated levels of sPD-1 have been detected in several cancers such as NSCLC (Non-small cell lung carcinoma), DLBCL, CLL (Chronic lymphocytic leukemia), NPC (Nasopharyngeal carcinoma), HCC, pancreatic adenocarcinoma, advanced rectal cancer, and metastatic melanoma (81–92) (Figure 3). Here, HOXD13 is linked to rectal cancer.