The highest infiltration with CD8+ TIL has been linked to a higher tumor mutational burden (TMB) in solid cancers [39,40], and despite the fact that CCA is not a highly mutated cancer, such as lung cancer or melanoma [41], several tumor-associated antigen (TAA)-derived epitopes were identified as candidate epitopes for immunotherapy [42]. The gene discussed is CD8A; the disease is cholangiocarcinoma.