Increased nuclear concentration of HDAC4 has been observed in the brains of individuals with Alzheimer’s disease (AD) [28,29] and ataxia telangiectasia [30], as well as in mouse models of AD [28,31,32], CDKL5 disorder [7], 2q37 deletion syndrome [3] and Parkinson’s disease [33,34]. The gene discussed is CDKL5; the disease is Alzheimer disease.