Histone deacetylase 6 (HDAC6) has been identified in the activation of STAT3 and upregulation of PD-L1 in melanoma.37,38 H3K4me3 can be catalyzed a promote PD-L1 transcription in pancreatic cancer and melanoma.39–41 At the level of RNA regulation, inflammatory signalling, aberrant oncogenic signalling and indirect regulation by miRNA are summarized. This evidence concerns the gene STAT3 and melanoma.