CD274 and viral infectious disease: It has been seen with neuroblastoma that viral infection promotes immunogenicity of tumour cells—this finding led to the study by Boes and Meyer-Wentrup (2015), who showed that triggering TLR3 promotes PD-L1 upregulation and IL-8 secretion and that this can be applied to combination therapies using ICBs and synthetic TLR ligands [105].