A study using scRNA seq showed an increase in inhibitory checkpoint receptors like T cell immunoglobulin and mucin-containing protein 3 (TIM3), lymphocyte-activation gene 3 protein (LAG-3), and T cell immunoreceptor with Ig and ITIM domains (TIGIT) on the CD8 T cells in CCA [157]. This evidence concerns the gene TIGIT and cholangiocarcinoma.