IFNG and cholangiocarcinoma: In contrast, Vδ2 γδ T cells exhibited varying degrees of IFN-γ secretion in response to 100 nM PTA-pretreated CCA, indicating that the specific lysis of CCA by Vδ2 γδ T cells is more sensitive than the production of IFN-γ by Vδ2 γδ T cells.