For example, mutations in ACVR1, FGFR3, PTHrP, and GLI2 genes result in fibrodysplasia ossificans progressive (FOP) [18,19], achondroplasia (ACH) [20], brachydactyly type E2 [21], and Culler–Jones syndrome [22], respectively. Here, PTHLH is linked to achondroplasia.