CD274 and cancer: The metabolic state of the tumor microenvironment can also affect immune responses, with altered metabolic pathways potentially leading to immune suppression and resistance to therapy, such as lactate and acidosis (Warburg effect as discussed earlier), hypoxia (upregulating PD-L1 in cancer cells and MSDCs, fostering immune evasion and resistance to ICIs), nutrient competition (depleted glucose and amino acids, such as glutamine) [168–170].