FOXP3 and cholangiocarcinoma: According to the latest scRNA-seq data analysis of CCA, T cells and NK cells in the CCA were divided into 8 distinct subsets, and it was found that CD8 + T cells were in an exhausted status, and CD4 + Foxp3 + Treg cells were enriched in the TME while exhibiting a highly immunosuppressive feature [47].