They found that MEK inhibitors not only had a direct killing effect on tumor cells, but also promoted tumor recognition by CD8+ T cells, increased the expression of cytokines such as IFN?, IL12, IL6 and TNFa, and prevented T cell depletion by downregulating PD-L1, CTLA-4, TIM-3 and LAG-3. The gene discussed is CD274; the disease is neoplasm.