RI-STAD-2 is a high-affinity peptide that interferes with the regulatory subunit RI of protein kinase A (PKA). It disrupts the binding between A-kinase anchoring proteins (AKAPs) and PKA-RI by mimicking the α-helical domain of AKAPs, interacting with the dimerization/docking (D/D) domain of PKA-RI. This disruption affects the activity and intracellular localization of PKA. RI-STAD-2 is utilized in studying the role of AKAPs and PKA-RI interactions in pathological processes such as cardiovascular diseases and cancer.