In Chinese medicine theory

Yin-yang disorder is the key to the occurrence and development of diseases. Attaining "natural harmony of Yin-yang"by regulating Yin-yang is the goal of Chinese medicine treating diseases. The authors think that part of the modern biological basis of Yin-yang disorder is uncontrolled DNA methylation（including abnormal hypermethylation and hypomethylation）. From the aspect natural harmony of Yin-yang in Chinese medicine

regulating abnormal hypermethylation genes and abnormal hypomethylation genes of diseases to normal condition is of great significance to treat diseases. The authors put forward that when making related researches of disease abnormal genes methylation levels by Chinese medicine intervention

not only should the demethylation effect be emphasized

but also the effect of promoting methylation should be considered

which is the bidirectional methylation regulation effect of Chinese medicine.