Kim SJ, Yoon DH, Kang HJ, et al. - In view of the observation that in Hodgkin lymphoma (HL) and primary mediastinal large B-cell lymphoma (PMBCL), the upregulated expression of the JAK/STAT pathway increases tumor growth, researchers investigated Janus kinase 2 (JAK2) as a therapeutic target and performed a prospective pilot study using ruxolitinib. They assessed JAK2 amplification using fluorescence in situ hybridization in 13 HL patients and six PMBCL patients. Oral administration of ruxolitinib at a dose of 20 mg twice daily for a 28-day cycle was done. The treatment was provided for up to 16 cycles or until progressive disease or intolerability. As per outcomes, ruxolitinib was active as single-agent against HL, especially in case of patients with JAK2 amplification. However, it showed no activity against PMBCL with or without JAK2 amplification.