Rago A, Ridola L, di Toritto TC. HBV infection in the era of T-cell engagers in multiple myeloma: unresolved challenges and unmet needs. Comment on: Hepatitis B virus reactivation following T-cell engager therapy in multiple myeloma despite negative hepatitis B core antibody serology: implications for screening in patients with hematological malignancies. Haematologica; https://doi.org/10.3324/haematol.2025.288942 [Early view].