All clusters were significantly enriched for cardiac genes: cluster 1 (Fig. 4a) contained genes with peaks in hydroxymethylation and expression at the embryonic stage, and included Myh7; cluster 2 (Fig. 4b) contained genes with peaks at the neonatal stage and included heart development genes such as Gata6; cluster 3 (Fig. 4c) contained key genes for adult heart metabolism, such as Ppara; and cluster 4 (Fig. 4d) contained genes with the highest expression and genic hydroxymethylation during hypertrophy, such as the cardiomyopathy-associated gene Xirp2. The gene discussed is XIRP2; the disease is cardiomyopathy.