Herein is reported a multi-function protein, characterized in that it comprises exactly one antigen presenting domain, exactly one antibody Fc-region, and at least one antigen binding site, wherein the antigen presenting domain comprises in N- to C-terminal direction either (i) a &bgr2-microglobulin, and (ii) the extracellular domains &alpha1, &alpha2, and &alpha3 of a class I MHC molecule with a relative frequency of less than 1%, or (i) a T-cell response eliciting peptide, (ii) a &bgr2-microglobulin, and (iii) the extracellular domains &alpha1, &alpha2, and &alpha3 of a class I MHC molecule with a relative frequency of 1% or more, wherein the antigen binding site binds to a cancer cell surface antigen.
