According to these reports, the gene expression was elevated in patients with Apert syndrome, as well as in mice harboring Fgfr1 Pro250Arg Pfeiffer syndrome mutation, thus confirming the direct correlation between the increased level of osteogenic proteins and the pathological ossification of sutures in both human and mice (Lemonnier et al. 2000, 2001; Zhou et al. 2000). Here, FGFR1 is linked to Pfeiffer syndrome.