KDM6A and KDM6B, also known as UTX and JNJD3, respectively, guide demethylation of the repressive mark H3K27me2/3: they have been reported to be mutated in around 10% of MM cases [59,60], and the presence of the mutations correlates with adverse prognosis [60,61]. This evidence concerns the gene KDM6A and Miyoshi myopathy.