Figure 2.

Pre-treated tumor with exhausted CD8⁺ T cells and tumor proliferating without immune inhibition. Radiation of tumors leads to double-stranded DNA breaks and downstream cGAS-STING signaling, which in turn increases Type 1 IFN release. Immunogenic cell death releases DAMPs such as HMGB1, HSP, GP96, and calreticulin. HMGB1 activates Dendritic Cells through TLR4-dependent pathway. Anti-CTLA-4 agents act on naïve and regulatory T cells while anti-PD-1 agents predominantly work on exhausted T cells.