A role for MEF2C in the regulation of bone development has been proposed on the basis of defects in MEF2C heterozygous mice,11 GWAS in patients with osteoporosis,6–8 and its role in regulating SOST expression.15,16,36 However, despite extensive study of the function of MEF2C in bone formation and mineralization, the importance of MEF2C in regulating osteoclasts and related bone resorption remains unclear. Here, SOST is linked to osteoporosis.