- CD26-mediated signaling for T cell activation occurs in lipid rafts through its association with CD45RO. Ishii, T., Ohnuma, K., Murakami, A., Takasawa, N., Kobayashi, S., Dang, N.H., Schlossman, S.F., Morimoto, C. Proc. Natl. Acad. Sci. U.S.A. (2001)