NPPA and infection: We found that infection with cardiotropic viruses significantly enhanced the expression of CHOP, cleaved caspase-3, the proapoptotic protein BAX and the heart failure marker atrial natriuretic peptide (ANP) while reducing the expression of the antiapoptotic protein BCL-2 in both human (Supplementary Fig. 1i) and mouse (Fig. 1h) cardiomyocytes.