IDH1 and acute myeloid leukemia: The authors demonstrate that methylation of a CTCF site downstream of FIP1L1 leads to loss of insulation and upregulation of the neighbouring oncogene PDGFRA. Given the prevalence of IDH1/2 and TET2 mutations in AML, it is tempting to speculate that similar mechanisms are at play in this disease (Cancer Genome Atlas Research Network et al., 2013a; Marcucci et al., 2010; Papaemmanuil et al., 2016).