Immunohistochemical Analysis of TMA Specimens

In the ZSH cohort, TMAs containing 259 ICC specimens were constructed as previously described [31 (link)–33 (link)]. For IHC staining of TMAs, following blocking endogenous peroxidase and antigen retrieval, the slides were stained using antibodies of CD8 (1:100, Cat# ab101500, Abcam, Cambridge, UK), Foxp3 (1:100, Cat# ab20034, Abcam), CD73 (1:500, Cat# 13160S, CST, Danvers, USA), HHLA2 (1:100, Cat# ab214327, Abcam), CD68 (1:8000, Cat# ab213363, Abcam), and CD163 (1:500, Cat# ab189915, Abcam). IHC staining of the TMA slides was performed according to the procedures described before [32 (link)].