CD274 and lung adenocarcinoma: Further, a lncRNA isoform of PD-L1, generated by alternative splicing, can promote lung adenocarcinoma progression, and the underlying mechanism involves enhancing c-MYC activity.127 Analysis of PD-L1 in peripheral blood mononuclear cells by He et al128 identified a novel PD-L1 isoform, with exon 2 spliced out.