- SLC5A8, a sodium transporter, is a tumor suppressor gene silenced by methylation in human colon aberrant crypt foci and cancers. Li, H., Myeroff, L., Smiraglia, D., Romero, M.F., Pretlow, T.P., Kasturi, L., Lutterbaugh, J., Rerko, R.M., Casey, G., Issa, J.P., Willis, J., Willson, J.K., Plass, C., Markowitz, S.D. Proc. Natl. Acad. Sci. U.S.A. (2003)