Our findings would provide information for better clinical application of Tanshinone I. However, there are remaining questions such as what is the binding site of Tan I to EZH2 protein, how the specificity of this binding is achieved, what are the differences and similarities between different Tanshinones as their chemical structural formula are similar, and is Tan I effective in other types of cancer cells? The gene discussed is EZH2; the disease is cancer.