Programmed cell death 1 ligand 2 (also known as PD-L2, B7-DC) is a protein that in humans is encoded by thePDCD1LG2 gene. PDCD1LG2 has also been designated as CD273 (cluster of differentiation 273). Involved in the costimulatory signal, essential for T-cell proliferation and IFNG production in a PDCD1-independent manner. Interaction with PDCD1 inhibits T-cell proliferation by blocking cell cycle progression and cytokine production.