Highly interestingly, by serial sequencing of TET2, ASXL1, EZH2, DNMT3A, and IDH1/2 in ET and PV patients treated with pegylated IFN-alpha2a, Quintas-Cardama et al. showed that the frequency of mutations in genes outside of JAK2 was higher in patients failing to achieve a complete molecular remission (CMR) (56%) versus those achieving CMR (30%), although this difference did not reach statistical significance. The gene discussed is IDH1; the disease is acquired polycythemia vera.