So in fact, what we can do is we can methylate one of the nitrogen atoms in that ring. And by methylating this nitrogen that creates stere hindrance and that forces the bending of that protoporphin ring. And now that we have formed this transition state analog whose structure resembles the transition state structure in that particular catalytic process, we can now expose, we can use this molecule, this transition state analog, as an antigen, essentially expose it to a plasma cell. The plasma cell will, in turn, basically begin building antibodies that contain an active side that has a complementary structure to this particular antigen. And so, once we build that antibody, the antibody will be easily able to fit those protoporphrine molecules into the antibody active side. And that antibody will, in turn, have the catalytic ability to basically transform or insert that se atom into the centering of that particular protoporphine.