BTLA marks a less cytotoxic T-cell subset in diffuse large B-cell lymphoma with high-expression of checkpoints.

•Expression of BTLA is high in the microenvironment of DLBCL.•The cytotoxicity and differentiation of BTLA+ T cells were analyzed.•High BTLA expression is correlated with advanced stage of DLBCL.•Our data provide the first evidence that increased BTLA predicts a poor prognosis in patients with DLBCL.•Our results hint that the blockade of BTLA may represent a new treatment strategy for DLBCL.