Summary:Tissue polypeptide antigen, measured by both a polyclonal antibody (TPA IRMA Prolifigen®) and a monoclonal antibody prototype kit (TPA-M IRMA Prolifigen®), and the tissue polypeptide specific antigen were evaluated. The markers were measured in 266 serum samples and in 291 tumour cytosols from patients with primary breast cancer. The three markers were available in matched pairs of both serum and cytosol from the same patient in 144 cases.