REPS1 and neoplasm: Nevertheless, a significantly higher percentage of Reps1 (MC38 neo-antigen)-reactive CD8+ T cells was present within MC38/Nb1 (12.6 ± 3.6%) compared to MC38/BCII10 (4.6 ± 3.3%) tumors, suggestive of an enhanced anti-tumor CD8+ T cell response (Figure 7B).