Figure 1.

Neoantigen presentation and T cell responses. Cellular proteins are degraded by the Ub-proteasome. Some peptide products are transported and further processed in the ER, then loaded onto MHC-I, and presented on the cell surface. (a) Autologous T cells cannot recognize self-antigens. In contrast, (b) mutant proteins resulting from tumor somatic mutations yield mutant peptides, which facilitate MHC-I interaction or TCR recognition depending on the mutant position. By responding to the neoantigen, T cells proliferate and show activated phenotypes with tumoricidal capacity.