Alexa Fluor® 488 Mouse Anti-Human CD274 Antibody (29E.2A3)

CD274, also known as PD-L1 (Programmed Death-Ligand 1), is a ~33 kDa type I transmembrane glycoprotein of the immunoglobulin superfamily that functions as the key ligand for the inhibitory receptor PD-1 on T cells; upon IFN-γ–driven up-regulation on dendritic cells, macrophages, normal epithelia and many tumors, its engagement of PD-1 delivers a “stop” signal that blocks T-cell receptor signaling, suppressing proliferation, cytokine production and cytotoxic activity, thereby maintaining peripheral tolerance and preventing autoimmunity, but is exploited by cancers to evade immune destruction, making the PD-1/PD-L1 axis a central target for modern checkpoint-inhibitor immunotherapies.