Ankyrin Repeat, PEST sequence and Proline-rich region (ARPP), also known as Ankyrin repeat domain-containing protein 2 is a protein that in humans is encoded by the ANKRD2 gene. ARPP is a member of the muscle ankyrin repeat proteins (MARP), which also includes CARP and DARP, and is highly expressed in cardiac and skeletal muscle and in other tissues. Expression of ARPP has been shown to be altered in patients with dilated cardiomyopathy and amyotrophic lateral sclerosis. A role for Ankrd2 in tumor progression and metastases spreading has also been described.