• Tumor Infiltrating Lymphocytes (TILs) from solid tumors can be characterized and isolated based on their cytotoxic activity.• Thousands of functional, paired T-cell Receptor (TCR) α- and β-chain sequences can be obtained.• High-throughput droplet-based co-encapsulation of TILs and tumor cells enables functional characterization and sequencing, potentially revealing neoantigens and escape mutations.
