The results of two more recent studies identify two additional human disease-associated proteins that are sumoylated, amyloid precursor protein (APP), and lamin A. APP sumoylation modulates Aβ peptide levels, suggesting a potential role in Alzheimer's disease, and decreased lamin A sumoylation due to mutations near its SUMO site has been implicated in causing some forms of familial dilated cardiomyopathy.