CD274 and neoplasm: For instance, one of the major breakthroughs has been the introduction of biomarkers such as programmed cell death ligand-1 (PD-L1) expression and tumor mutational burden (TMB) in predicting response to immunotherapy and even though markers for monitoring treatment response are lacking, circRNAs have demonstrated an ability to regulate gene expression by targeting known miRNA targets which, amongst others include PD-L1 (Michaelidou et al., 2020).