Multiple studies confirm that enhanced CD4+ and CD8+ infiltrates (also in combination with low numbers of macrophages) in CCA and extrahepatic biliary tract cancer are associated with improvement of overall survival, fewer lymph node metastases and reduced venous and perineural invasion [53–57], whereas small amounts of CD8+ TILs are associated with poor overall survival [58]. The gene discussed is CD4; the disease is cholangiocarcinoma.