Several general points are relevant to interpretation of these disease-association data. First, replication studies are required to confirm associations from GWAs. For the reasons given in the box, we regard very low P values (say P<5×10-7) in our comparatively large sample size as strong evidence for association, and indeed all or most of the loci we find at this level are either already known or have now been confirmed by subsequent replication. Such replication studies are also the substrate for efforts to determine the range of associated phenotypes and to identify and characterize pathologically relevant variation.
