Therefore,KRAS/LKB1 mutations in cancer cells not only establish a non-T cell, inflamed TME including reduced infiltration of CD3+, CD4+, CD8+ T cells and low expression of PD-1, but also help the cancer cells to cope with harsh conditions in the TME, when metabolites such as arginine become limited depending on the immune status (Figure 2D). The gene discussed is KRAS; the disease is cancer.