CD274 and neoplasm: A number of studies have evaluated differences in the number of immune cells in HPV+ versus HPV- tumour tissues, including tumour-infiltrating lymphocytes (TIL) [24,25] and B-cells [22], or the differential expression of immune checkpoint receptors PD-1 and PD-L1 in these tumours [26,27], often summarized as the tumour immune microenvironment (TIME).