HSSVD approximation result for all samples. (A) Variance approximation; (B) mean approximation. Blue represents cancer samples, and pink represents normal samples in the sidebar. Genes and samples are ordered by hierarchical clustering. Red represents large values, and green represents small values. Only the variance approximation can discriminate between cancer and normal samples. More importantly, within the same gene, the heatmap for the variance approximation indicates that cancer patients have larger variance than normal individuals. This result matches the conclusion in ref. 19. In addition, the cDMRs with the greatest contrast variance across cancer and normal samples are highlighted by the variance approximation, whereas the original paper does not provide such information.