- The CD20 calcium channel is localized to microvilli and constitutively associated with membrane rafts: antibody binding increases the affinity of the association through an epitope-dependent cross-linking-independent mechanism. Li, H., Ayer, L.M., Polyak, M.J., Mutch, C.M., Petrie, R.J., Gauthier, L., Shariat, N., Hendzel, M.J., Shaw, A.R., Patel, K.D., Deans, J.P. J. Biol. Chem. (2004)