Figure 1. APLP2 is associated with MHC class I molecules in EWS cells. The W6/32 antibody was used to immunoprecipitate folded, MHC class I molecules from TC71 and A673 cell lysates. As a control, the procedure was also performed with no immunoprecipitating antibody (lanes labeled as “Protein A-Sepharose”) and with an irrelevant IgG (isotype control) antibody (anti-CD3 antibody, lanes labeled as “Control Ab”). Immunoprecipitates were then probed by immunoblotting with the HC10 antibody against the MHC class I heavy chain (MHC-I HC) and APLP2. The results shown are representative of 6 separate experiments.