SPDL1 and biliary tract neoplasm: The relationship between higher baseline sPD-L1 levels and shorter OS had been revealed in many other types of cancers, including esophageal cancer, [89, 90], GC, [22, 62, 91, 92, 93, 94] HCC, [72, 95, 96, 97, 98, 99, 100] biliary tract cancer, [101] RCC, [18, 102] upper tract urothelial carcinoma, [103] lymphoma, [104–107] OC, [7, 108] CRC, [109, 110] soft tissue sarcoma (STS),[111, 112] glioma, [113, 114] and PDAC [59, 115].