CA9 and facioscapulohumeral muscular dystrophy 2: HsMORC2 down-regulates Carbonic Anhydrase IX (CAIX) expression in tumor cells by recruiting histone deacetylase 4 to the CAIX promoter, which in turn alters histone acetylation levels (Shao et al., 2010), while SMCHD1 is involved in silencing the D4Z4 metastable epiallele whose overexpression leads to facioscapulohumeral muscular dystrophy type 2 (Lemmers et al., 2012).