CD31 (PECAM-1) TFA is platelet endothelial cell adhesion molecule-1, serves as the endothelial cell-specific receptor of clostridium perfringens b-Toxin ( CPB ). CD31 TFA is also an ER-MP12 antigen , acts as a linker between mechanical stress, metabolism and inflammation. CD31 TFA peptide is able to sustain phosphorylation of the CD31 ITIM 686 and of SHP2 and to inhibit TCR -induced T-cell activation -.