CD9 and carcinoma: A similar study in rat carcinoma confirmed TSPAN8 interactions with CD9, CD81 and CD151, as well as revealed non-tetraspanin partners, including α3β1 integrins and other signaling molecules, such as the Ig superfamily member FPRP (prostaglandin F2α receptor regulatory protein), type II PI4K (phosphatidylinositol 4-kinase) and EpCAM (epithelial cell adhesion molecule) [46].