Immunocytologic staining for RHAMM/CD168 in naive versus transfected COS7 cells. The cell line K562 served as a positive control (D). ICS for RHAMM/CD168 in RHAMM/CD168 single-transfected COS7 cells (E) and RHAMM/CD168&HLA-A2 permanently double-transfected COS7 cells (F) showed a strong expression of RHAMM/CD168 in all transfected cells, whereas RHAMM/CD168 protein was not expressed in naive COS7 cells (A), COS7 cells mock transfected with the vector pBudCE4.1 (B), or COS7 cells solely transfected with HLA-A*0201 but not with RHAMM/CD168 (C). All photomicrographs were taken at a magnification × 100.