IFNG and cholangiocarcinoma: In addition, significant levels of degranulation and IFN-γ production were observed in Vδ2 γδ T cells when exposed to PTA-sensitized CCA cells through a CD107a-based degranulation assay and a flow cytometry-based intracellular IFN-γ staining assay, demonstrating that Vδ2 γδ T cells specifically recognized PTA-sensitized CCA cells (Supplementary Figure S3C,D).