JAK2 and myeloproliferative neoplasm: Many drugs are now under investigations targeting different pathways critical for MPN development, such as the JAK-STAT (JAK2-inhibitors: INCB018424, TG101348, CEP701, CYT387, SB1518, AZD1480, XL019, LY2784544), the mTOR (everolimus), the MAPK (erlotinib), and the NF-Kb (bortezomib) pathways, or act through remodeling chromatin with a key role in epigenetics (givinostat, panobinostat, vorinostat).