BTLA and non-Hodgkin lymphoma: To understand the differences in capacity of B-NHL cells to activate healthy donor T-cells in the presence of epcoritamab, we investigated the association between B-NHL subtype, treatment status, and CD20 expression level and between expression of ligands of the immune checkpoint molecules PD-1, LAG3, and BTLA: PD-L1, HLA-DR, and HVEM (tumor necrosis factor receptor superfamily member [TNFRSF]14), with allogeneic T-cell activation.