Both CD4+ and CD8+ TILs proportions in spontaneous and transplanted UPS tumours were low: CD4+ 0.8% +/- 0.2 and 1.8% +/- 0.4, respectively; CD8+ 1.1% +/- 0.4 and 3.7% +/- 2.0, respectively (Fig 4B). The gene discussed is CD4; the disease is undifferentiated pleomorphic sarcoma.