Novel monoclonal antibodies that specifically bind to KAAG1 are described. Insome embodiments, the antibodiesblock the biological activity of KAAG1 and are useful in composition incertain cancers, more particularly in cancers that haveincreased cell surface expression of KAAG1, such as ovarian, renal, lung,colorectal, breast, brain, and prostate cancer, as well asmelanoma. The invention also relates to cells expressing the monoclonalantibodies and antigen binding fragments such as humanizedand chimeric antibodies. Additionally, methods of detecting and treatingcancer using the antibodies and fragments are alsodisclosed.
