In order to identify proteins that bind to the PDZ domain of Erbin, we tested the C-termini of several proteins in a yeast two-hybrid assay. ErbB2, APC, β-catenin, c-Rel and HTLV-1 Tax were identified as ligands of the PDZ domain of Erbin. The interactions were verified by co-immunoprecipitation experiments. These findings demonstrate the promiscuity of the PDZ domain of Erbin.