Although a number of clinical candidates that are known small molecule JAK inhibitors for myeloproliferative disorder therapy are being clinically developed, and FDA approval of pan-JAK inhibitor ruxilitinib for the treatment of intermediate or high-risk myelofibrosis has confirmed and validated JAK as a clinical target for myeloproliferative disorders, no selective JAK2 inhibitor has been investigated yet. Here, JAK2 is linked to myeloproliferative disorder.