Excuse my naive questions, but this left me very curious.<p>1) Have we reached a phase where the difficult part is finding the genes responsible for X? With the delivery being now boilerplate code (CRISPR?).<p>2) What exactly are the limitations of gene therapy?<p>3) How does aging fit into the picture? For example, if grey hairs are the result of cell aging/damaging, will we be able to reverse/restore it?