PKD1 and craniosynostosis: To investigate whether an association between PC1 and RUNX2 exists in craniosynostosis, we sought to modulate PC1 via an antibody which binds to the mechanosensing extracellular N‐terminal domain of the protein, namely, IgPKD1, and assess its effect on the activation (phosphorylation) status of RUNX2 in trigonocephaly and dolichocephaly cranial suture cells.