Both these receptors are expressed in multiple epithelia, including salivary gland epithelium,62,63,105,114–116 where they contribute to increases in inflammation,37,63,105,111,113 and deletion63 or inhibition37 of the P2Y2R or P2X7R, respectively, diminishes inflammation and enhances saliva production in the NOD.H-2h4 DKO mouse model of SS.37 This evidence concerns the gene P2RY2 and synovial sarcoma.