Although the CTLA-4 antibody ipilimumab391 has become a first-line therapy in metastatic melanoma,392,393 the application of the CTLA-4 antibody still needs to be explored in hematological malignancies.394 The phase 1 part of a phase 1/2 trial (NCT00089076) of ipilimumab in relapsed or refractory B-NHLs induced an ORR of 11.1% (CR 5.6%).395 Trials of ipilimumab combined with other agents, such as nivolumab (NCT02408861) in HIV-associated HL, are ongoing. Here, CTLA4 is linked to metastatic melanoma.