- Identification of Id4 as a regulator of BRCA1 expression by using a ribozyme-library-based inverse genomics approach. Beger, C., Pierce, L.N., Kruger, M., Marcusson, E.G., Robbins, J.M., Welcsh, P., Welch, P.J., Welte, K., King, M.C., Barber, J.R., Wong-Staal, F. Proc. Natl. Acad. Sci. U.S.A. (2001)