Part of the key, in both the trials and I hope in the clinic, is that they can use genetic/antibody screening to determine whether one of these PD-1 inhibitors

Part of the key, in both the trials and I hope in the clinic, is that they can use genetic/antibody screening to determine whether one of these PD-1 inhibitors will help you against a cancer... however, it's complicated both for scientific and ethical reasons, when you're running a trial and treating patients. See the excellent Drug Discovery blog _In The Pipeline_ by Derek Lowe: http://blogs.sciencemag.org/pipeline/archives/2016/08/23/not-so-fast-on-the-pd-l1-comparisons http://blogs.sciencemag.org/pipeline/archives/2016/08/23/not... http://blogs.sciencemag.org/pipeline/archives/2017/05/25/an-approval-like-no-other http://blogs.sciencemag.org/pipeline/archives/2017/05/25/an-...