MMP9 and fragile X syndrome: Recent studies have demonstrated that minocycline treatment, an FDA-approved antibiotic that can inhibit MMP9 activity, reverses electrophysiological and/or behavioral disturbances in FMR1 KO mice (Bilousova et al., 2009; Lovelace et al., 2020), drosophila FXS models (Siller and Broadie, 2011), and FXS individuals (Leigh et al., 2013).