- Neurofibromatosis type 1 gene haploinsufficiency reduces AP-1 gene expression without abrogating the anabolic effect of parathyroid hormone. Yu, X., Milas, J., Watanabe, N., Rao, N., Murthy, S., Potter, O.L., Wenning, M.J., Clapp, W.D., Hock, J.M. Calcif. Tissue Int. (2006)