Why does individually detecting 5mC and 5hmC matter? 

The four traditional bases make up the foundational genetic code for all living systems. DNA methylation affects how and when genes are expressed, but the two methylation marks 5mC and 5hmC have opposing effects: 5mC reduces expression, or “turns off” genes, and in contrast, 5hmC increases gene expression, and “turns on” or “primes” genes. These two marks have unique functions, and capturing their distinct information, alongside traditional genetic information, is essential to understanding normal biology and disease states.