CD274 and cancer: Although the relationships between calcium intake and cancer risk have not been consistent and the exact mechanism about how calcium may help reduce the risk of some cancer types is unclear, we guess one of the possible mechanisms for the reduced risk by the high calcium intake is that the positive charges of calcium can neutralize the membrane charges as well as what was observed in T cell signaling24,44 and release PD-L1-CD from the membrane, which leads to the reduction of PD-L1 levels in some cancer cells.