It is posited that, for the small proportion of the neoepitopes that mediate tumor control in vivo and have a high affinity for MHC I (see Table 1, and some in Table 2), the pMHC-TCR affinity would, of necessity, be low, so that the pMHC-TCR avidity is also low: as recently observed (121–124), only CD8+ T cells with low to intermediate avidity, but not those with high avidity are able to mediate tumor control. The gene discussed is CD8A; the disease is neoplasm.