RPS6KA3 and Coffin-Lowry syndrome: RSK2 deficient human CLS cells are abolished the histone H3 phosphorylation at serine 10 by EGF stimulation, and re-introduction of the wild-type RSK2 to RSK2 deficient CLS patient cells restores EGF-induced histone H3 phosphorylation at serine 10 (61).