**7. Perspectives and conclusions**

As stated in the abstract and introduction, the issue of structural diversity (heterogeneity) of antibodies has become a big subject along with the development of antibody drugs and catalytic antibodies. This subject has not been solved for a long period, because many difficult and complex problems were existing. For this long-period unsolved problem, copper ion showed a drastic effect and gave one of the answers for solving the structural diversity issue. Note that the antibody and/or the subunits must have a defined structure for practical use.

In recent years, many possibilities of the development of antibody drugs and catalytic antibodies have been reported by research groups throughout the world. This article offers huge insights into the development of catalytic antibodies, maybe, as well as antibody drugs. Because the preparation can be standardized, many scientists and engineers will easily be able to produce the defined structure and the same functional antibody under any circumstances and anywhere in the world.
