SOD1 and in situ carcinoma: The molecular structures of different anthraquinone monomers are very similar (Figure 1); for example, CHR and rhein almost have same molecular structure, except one of CHR's methyl groups is substituted by rhein's carboxyl group; they both inhibited the expression of cleave caspase-3 and attenuated the activity of SOD in CIS [29, 35]; however, which effects are stronger is still unknown.