P2Y4 is a 365-amino acid 7 transmembrane protein. It has been shown that, when expressed in a mammalian cell line, the receptor protein was activated specifically by UTP and UDP, but not by ATP and ADP. Activation of P2RY4 resulted in increased inositol phosphate formation and calcium mobilization. Adrian et al, anazlyed the espression of several purinergic receptors during differentiation in a promyelocytic leukemia cell line. Granulocytic differentiation was induced by dimethylsulfoxide, and a monocytic/macrophage phenotype was induced by phorbol esters. P2RY4 was highly expressed in uninduced promyelocytes, and its expression decreased slightly following both granulocytic and monocytic differentiation.