Cells obtained from Coffin-Lowry syndrome (CLS) patients, caused by the deletion, nonsense, and missense mutations of RSK2, show defects in EGF-induced histone H3 phosphorylation, and introduction of RSK2-wt into CLS patient cells restores p-H3-S10 protein levels [16]. The gene discussed is RPS6KA3; the disease is Coffin-Lowry syndrome.