CD8A and bile duct cancer: The favourable prognostic significance of the presence of tumour-infiltrating CD8+ T cells was previously reported in a variety of cancers, including colorectal cancer, oesophageal cancer, pancreatic cancer, bile duct cancer and gallbladder cancer (Naito et al, 1998; Nakano et al, 2001; Schumacher et al, 2001; Cho et al, 2003; Nakakubo et al, 2003; Oshikiri et al, 2003; Fukunaga et al, 2004).