As the PD-L1 mRNA level significantly decreased in melanoma patients responding to therapy and increased in patients that progressed during treatment, the authors suggest that PD-L1 mRNA level in plasma-derived exosomes could be used to monitor response of melanoma patients to the anti-PD-1 therapy although larger cohorts of melanoma patients will be needed to confirm this finding [108]. This evidence concerns the gene CD274 and melanoma.