It's not unthinkable - in the case of Keytruda (a checkpoint inhibitor for lung cancer), it works way better for smokers than for non-smokers, for understood re

It's not unthinkable - in the case of Keytruda (a checkpoint inhibitor for lung cancer), it works way better for smokers than for non-smokers, for understood reasons. You're much more likely to have lung cancer if you smoke than if you don't -- but once you DO have lung cancer, a history of smoking makes keytruda more likely to work.