HSPG2 and fragile X syndrome: Importantly, HSPG/MMP levels and Wg signaling are altered in parallel in dfmr1 null animals, and the genetic reduction of Dlp, or genetic/pharmacological reduction of secreted MMP1, both correct Drosophila FXS disease model phenotypes (Siller and Broadie, 2011; Friedman et al., 2013).