Commentary: Grading the credibility of molecular evidence for complex diseases

Dissecting the aetiology of complex diseases has been a great challenge for biomedical research, including epidemiology. Several thinkers, 1–4 including Buchanan et al. 5 recently, have focused on the unquestionable difficulties of this ambitious enterprise and the great obstacles encountered in the way. Some of them have ended up with a futility outlook. Over more than a decade, the debate has ranged wild on whether epidemiology has reached its limits, 6 is either dead or in a vegetative state, should call it a day, and whether ‘it is time for scientists to re-think the quest’ and realize that ‘base metal cannot be turned to gold’. 5