Beyond T cells: B cells in immune checkpoint blockade.

Immune checkpoint blockade is usually framed as a T cell-directed therapy. Recent studies challenge this view by showing that B cells, plasma cells, and tumor-reactive antibodies are reshaped by programmed cell death protein-1 and cytotoxic T-lymphocyte-associated protein-4 blockade and can contribute to efficacy. Humoral immunity should therefore be integrated into models of checkpoint efficacy.