1. Unit of Hematology Department of Medicine at Huddinge Karolinska Institutet Stockholm Sweden
2. Unit of Hematology Karolinska University Hospital Stockholm Sweden
3. Department of Oncology Oslo University Hospital Oslo Norway
4. KG Jebsen Center for B‐Cell Malignancies Oslo Norway
5. Department of Oncology Academic Hospital Uppsala Sweden
6. Department of Hematology Rigshospitalet Copenhagen Denmark