STAT3 and non-small cell lung carcinoma: PD-L1 expression is regulated by NF-κB through the RELA/p65-MUC1-C complex [64], as well as by c-Jun and the activator protein-1 (AP-1), which binds the first intron of CD274, in a STAT3-dependent way in KRAS-mutant NSCLC [20].