JAK2 and primary myelofibrosis: To investigate the role of JAK2 pathway in ALS, we used R723, which is a selective small-molecule JAK2 inhibitor originally developed by Rigel Pharmaceuticals Inc, (San Francisco, CA, USA) for the treatment of myeloproliferative neoplasms such as polycythemia vera, essential thrombocythemia and primary myelofibrosis (Additional file 2: Figure S1A) [15].