NPPB and heart failure: Ankrd1 and Ankrd23 are stress-inducible ankyrin repeat proteins that are elevated in dilated cardiomyopathies.26,27Xirp2 encodes cardiomyopathy-associated protein 3 and is up-regulated in CMs in response to stress.28,29 Expression of Nppb, a canonical heart failure gene, was similarly elevated (Figure 3E).