Hence, a PD-L1 and/or STAT3 blockade with anti-PD-L1 or anti-STAT3 is considered as a potent treatment strategy in several cancers [11,12] since the overexpression of PD-L1 and STAT3 is observed in melanoma, pancreatic, lung and other types of cancer cells [13,14]. Here, STAT3 is linked to melanoma.