- Uroplakin IIIb, a urothelial differentiation marker, dimerizes with uroplakin Ib as an early step of urothelial plaque assembly. Deng, F.M., Liang, F.X., Tu, L., Resing, K.A., Hu, P., Supino, M., Hu, C.C., Zhou, G., Ding, M., Kreibich, G., Sun, T.T. J. Cell Biol. (2002)