(A) ELISPOT assay of BORIS subfamily 6-specific and non-specific CTL clones. The reactivity for BORIS C34_24(9) peptide were analyzed by ELISPOT assay. HIV peptide and peptide (-) were used as negative controls. (B) Sphere-formation inhibition assay. BORIS C34_24(9) peptide specific CTL clone (3B9) or non-specific CTL clone (5H6) were co-cultured with SBC5 cells in a sphere-forming condition. After 6 days’ culture, the numbers of spheres were counted. Upper panel indicate the numbers of spheres, and data are shown as means ± SD. Lower panel indicates representative images of spheres. Magnification, x 100. Bar scale is 100 μm.