HLA class II molecules play a pivotal role in antigen presentation to T lymphocytes. This chapter analyzed the expression of these molecules in different human tumors and their role in cancer progression. The possible connection between tumor HLA class II expression and the pathogenesis of autoimmune diseases is discussed.
Keywords: Antigen presenting cells; Cytokynes; HLA-II & autoimmunity; HLA-II in tissues; HLA-II in tumors; Immunohistochemistry; Interferon; Tumor infiltrating lymphocytes; Tumor prognosis; Tumor rejection.