– CD31 TFA, also known as platelet endothelial cell adhesion molecule-1 (PECAM-1), functions as the specific receptor for Clostridium perfringens beta-Toxin (CPB) in endothelial cells. It is recognized as an ER-MP12 antigen and plays a pivotal role in connecting mechanical stress, metabolism, and inflammation. Additionally, the CD31 TFA peptide facilitates the phosphorylation of CD31 ITIM 686 and SHP2, further inhibiting TCR-induced T-cell activation [1]-[5].