WNT4 and osteoporosis: Recently, genome-wide association studies (GWASs) have identified several osteoporosis-related genes, such as catenin (cadherin-associated protein) beta 1 (CTNNB1), sclerostin (SOST), low-density lipoprotein receptor-related protein 4 (LRP4), LRP5, wingless-type MMTV integration site family, member 4 (WNT4), WNT5B, and AXIN1 [5].