Me being comfortable with the state of research and the fact that having more cell lines would've likely done nothing for our current understanding are two different things. The frank truth is, we're far from even understanding how epigenetics factor in differentiation between induced pluripotent stem cells and embryonic ones and which one is better for getting the results you want. The expense of the medium to grow the cells and the fact that it takes a month to see results of what you're doing, the economics, is far more impactful on why we haven't seen progress than the availability of cell lines.