PD-L1 [SEP] found in taxon
is mostly responsible for upregulation of PD-L1 on macrophages by LPS or interferon-gamma, but is not at all responsible for its constitutive expression before activation in these mice.
It was also shown that PD-L1 is constituvely expressed on mouse Ly6C nonclassical monocytes in steady state. 
Regulation Role of microRNAs.
Resting human cholangiocytes express PD-L1 mRNA, but not the protein, due to translational suppression by microRNA miR-513. Upon treatment with interferon-gamma, miR-513 was down-regulated, thereby lifting suppression of
PD-L1 protein. In this way, interferon-gamma can induce PD-L1 protein expression by inhibiting gene-mediated suppression of mRNA translation.
Regulation Epigenetic regulation.
PD-L1 promoter DNA methylation may predict survival in some cancers after surgery.
Clinical significance.
Clinical significance Cancer.
It appears that upregulation of PD-L1 may allow cancers to evade the host immune system. An analysis of 196 tumor specimens from patients with renal cell carcinoma found that high tumor expression of PD-L1 was associated with