DPP4 and synovial sarcoma: Even in short assays (48 to 72 h), the proportion of TNFR2+ CD26− cells was significantly reduced (t test, p < 0.05 for TNFR2 antagonist ≥ 12.5 μg/ml) in SS patient samples samples; Fig. 2a and Supplementary File S3a).