Since hypertension is a complex trait, with susceptibility related to SNPs in multiple genes as well as the interactions between them, the ability to navigate the network of candidate genes is an important facility of the resource. Viewing the set of candidate genes in the Java graphical interface provides the mechanism for this. Figure 6 shows a screen snapshot of the graphical interface for the hypertension candidate gene network. Strongly associated genes cluster in the display. In particular, in this case, the four primary blood pressure regulation pathways form distinct groups, indicated by the black ovals. Among these, the renin-angiotensin pathway (A), controlling absorption of sodium, is the most studied, and most of its genes have been implicated in monogenic types of hypertension (indicated by the oval gene symbols). The other pathways all influence blood pressure through vascular constriction via: (B), regulation by endothelin (EDN1); (C), regulation of natruretic peptide (NPPA, NPPB, NPPC); and (D), the bradykinin-killikrien pathway. Figure 7 shows a simplified version of the pathways and their inter-relationships, derived from browsing the interface, reviews [68,69], and on-line data
