Innovative technologies like array comparative genomic hybridization (arrayCGH), single nucleotide polymorphism (SNP) arrays and next-generation sequencing revealed recurrent mutations of genes implicated in epigenetic control such as ASXL1, EZH2, DNMT3A and TET2 in MDS and AML. The gene discussed is ASXL1; the disease is myelodysplastic syndrome.