Early in 2012, a research group in Japan described the presence of IgG4+ plasma cells in patients with cholangiocarcinoma, a rare form of hepatic cancer involving the bile ducts [97], The presence of the IgG4+ B cells was associated with increased frequency of CD4+Foxp3+ T cells and decreased CD8+ T cells, suggesting the evasion of immunosurveillance by CD8+ cytotoxic T cells. The gene discussed is CD8A; the disease is cholangiocarcinoma.