THY1 and neoplasm: All of the tumours were CD90-positive and CD45R-negative consistent with a diagnosis of TL, with the full range of immunophenotypes represented including CD4/CD8 double positive, double negative and single positive tumours, tumours where CD4 and/or CD8 were expressed along a continuum from high to low, and tumours with multiple distinct immunophenotypes (S3 Table).