Retina AMD interactome shows graded expression across AMD phenotypes. (a) AMD interactome assembled from retina Global Up, CNV Up and CNV Down disease modules assembled from three data sources: STRING , Ingenuity Pathway Analyzer (IPA), and the Bossi and Lehner  human protein-protein interaction dataset (PPI) (see Materials and methods). Parallelogram-shaped nodes indicate genes previously associated with AMD (Table S2 in Additional file 3). Exp, Db, and Text indicate Experimental, Knowledge/Database, and Text-mining components of the STRING interaction score, respectively. (b) Heat maps depicting macular expression levels as a function of AMD and pre-AMD phenotype (also see Figure S13 in Additional file 1). Expression levels were calculated as described in Figure 4. (c) Mean differential expression for each subnetwork in (b), organized by AMD/pre-AMD phenotype. Error bars represent standard error of the mean.