The histone demethylases KDM4C (JMJD2C) and KDM3C (JMJD1C) were recently identified as signaling effectors of mutated JAK2 and target genes of the transcription factor NFE2, which is overexpressed in myeloproliferative neoplasms [183, 186, 187]. The gene discussed is JAK2; the disease is myeloproliferative disorder.