HLA‐DP molecules were isolated from Epstein‐Barr virus transformed B cell lines by immunoprecipitation with monoclonal antibody B7/21.2 and subsequently analysed by two‐dimensional gel electrophoresis. The results obtained demonstrate that the HLA‐DP molecules that can be isolated from cells positive for the HLA‐DP specificities HLA‐DPw1, ‐DPw2 and ‐DPw4 display DP beta chain isoelectric point differences, whereas no DP alpha chain polymorphism was observed. These results suggest that the PLT defined HLA‐DP specificities (HLA‐DPw1, ‐DPw2 and ‐DPw4) are probably D