CD274 and melanoma: Patients with a high PD-1 and PD-L1 expression may have a worse prognosis and may require a more aggressive therapeutic approach or more intensive monitoring and are better candidates for PD-1/PD-L1 blockade-based immunotherapy, which has been shown to be effective in enhancing the immune response against tumors in various cancers, including melanoma and lung cancer [22,23,54].