JB, CP, WB, AC, JM, MM, NK, PN, AECB, ME, CHA, MK, RR, MS, CG, AM, IM and ZP have no conflicts of interest to declare. OP has received honoraria or travel support from Alexion, Gilead, Jazz, MSD, Neovii, Novartis, Pfizer and Therakos. He has received research support from Incyte and Priothera. He is member of advisory boards to Alexion, Equillium Bio, Jazz, Gilead, Novartis, MSD, Omeros, Orca Bio, Priothera, Sanofi, Shionogi and SOBI. HS reports having received personal fees from Incyte, Novartis, Sanofi, MAAT Pharma, Mallingkrodt and from the Belgian Hematological Society (BHS), as well as research grants from Novartis and the BHS, all paid to her institution. She has also received non-financial support from Gilead, Pfizer, Sanofi, the EBMT (European Society for Blood and Marrow transplantation) and the CIBMTR (Center for International Bone Marrow Transplantation Research).