CD274 and breast carcinoma: In this context, recent studies suggest that EMT associated upregulation of PD-L1 in cancer cells might be regulated in a context-dependent manner—as there was an increased recruitment of an active transcription histone mark (H3K4me3), at the expense of repressive histone marks (H3K9me3, H3K27me3), on the PD-L1 promoter in tumorspheres but not monolayer breast cancer cells [96].