PAK1 and craniodiaphyseal dysplasia: To shed some light on the mechanism of action of FRAX486 in CDD mouse brain, we analyzed the levels of phosphorylation of three autophosphorylation sites which mark the active state conformation of PAKs (phospho‐serine 144/141/139, P‐PAKs)48 and of the threonine 212 of PAK1 (P‐PAK1 Thr212), an important site for the regulation of cytoskeleton dynamics in neurons.17