The presence of cross-reactive (CR) antigens of the HLA-A and B specificities between donor and recipient carries a better graft outcome than an HLA match not taking it into account. This influence of CR antigens has been observed in the case of cadaver kidneys matched only for none or one HLA antigen. If two or more antigens are matched this effect is not seen anymore. This improved graft survival could not be explained on the basis of the number of transfusion nor the incidence of cytotoxic antibodies.