Finally, in addition to the transcriptional regulation of PD-L1, TNF-α-mediated nuclear translocation and downstream transactivation of p65 increase PD-L1 expression by transcriptionally upregulating CSN5, which functionally hydrolyzes the ubiquitin chain from ubiquitin-PD-L1 and further enhances the PD-L1 stabilization in breast cancer cells (167, 186). This evidence concerns the gene CD274 and breast cancer.