Multiple independent studies have shown that many CpG sites located in genomic region around 5′ upstream of HDAC4 gene are differentially methylated in the peripheral tissues of patients with AN (Booij et al., 2015; Kesselmeier et al., 2018; Subramanian et al., 2018; Sild and Booij, 2019; Steiger et al., 2019), further supporting the role of HDAC4 in the pathophysiology of EDs. The gene discussed is HDAC4; the disease is Ehlers-Danlos syndrome.