The point of this post (and what I realised during my PhD) was that for the most part this doesn’t matter; choice of targets and predicting the human efficacy of a therapy that works in a tube or mice is far more important and typically more ignored. People don’t focus on that because it’s a hard problem especially for math and computer people who think their absence is the reason cancer isn’t cured yet and come over to try and win the Nobel prize (and don’t; cue relevant xkcd).