RUNX2 and craniosynostosis: In contrast, our data showing that Fgfr2C342Y marrow stromal cells express significantly lower levels of Runx2 and tissue non-specific alkaline phosphatase mRNA, as well as significantly diminished alkaline phosphatase enzyme activity and mineralization, is in accordance with previous studies showing that S252W, C342Y, and P253R craniosynostosis-associated mutations in FGFR2 inhibit osteoblast differentiation [48–50].