Interestingly, alendronate, a drug currently used to treat osteoporosis (Al Lawati et al. 2025), is a potent inhibitor of PTPMEG (Opas et al. 1997) and has been shown to access the brain via systemic (Cibickova et al. 2007) or nasal administration (Zameer et al. 2021). This evidence concerns the gene PTPN4 and osteoporosis.