– cAMP-Dependent Protein Kinase Inhibitor β (PKI-β) is a member of the PKI family. As a member of the cAMP-dependent protein kinase inhibitor family,It has been shown that PKI-β is an extremely potent competitive inhibitor of cAMP-dependent protein kinase activity; this protein interacts with the catalytic subunit of the enzyme after the cAMP-induced dissociation of its regulatory chains. It may play a role in the protein kinase A (PKA) pathway by interacting with the catalytic subunit of PKA, and overexpression of this gene may play a role in prostate cancer.