While, as previously discussed, the GL261 model has over 4900 non-synonymous somatic mutations on whole-exome sequencing, SB28 tumor cells have 108 mutations, resulting in a total of 11 potential predicted neoantigens.12,62 SB28 tumors also have a relatively modest amount of tumor-infiltrating T cells, with PD-1 expression on 50% of CD8+ T cells in the tumor microenvironment. The gene discussed is CD8A; the disease is neoplasm.