CD274 and neoplasm: When PD1 binds with PD-L1 (programmed cell death ligand 1), it results in apoptosis of effector T-cells, which leads to immune escape of tumor.5, 6Also, it increases the synthesis of interleukin-10 cytokines, which suppress inflammatory responses.7In various studies, it is observed that overexpression of PD-L1 is seen in 50 to 90% of OSCC patients.