RIPK2 and familial dilated cardiomyopathy: Furthermore, the mRNA expression levels of the lysosomal protein transmembrane 5 (LAPTM5), ubiquitin C-terminal hydrolase L1 (UCHL1), and receptor-interacting serine/threonine kinase 2 (RIPK2) genes were markedly upregulated (by ≥1.8 fold) in the DCM tissue compared with the CNT tissue levels.