Given the current status of knowledge, the IO-specific DDPP gene set focuses on PDL-1, PDL-2, PD-1, CTLA-4, CD28, CD80, CD86, LAG-3, and TLR-4, together with specific markers of the presence of effector tumor-infiltrating immune cells: CD8A (cytotoxic lymphocytes T), CD16 (natural killer cells), and FOXP3 (T-regs cells). The gene discussed is CD28; the disease is neoplasm.