Co-expression network of ECM related genes showing significant differential expression in obese WAT. The relationships of differentially expressed genes annotated with structural or functional GO categories related to ECM were determined in order to build a co-expression network. The absolute value of a Spearman's correlation coefficient Rs ≥ 0.8 between expression profiles was used as co-expression threshold to relate co- or inversely expressed genes. Red lines indicate co-expression relationships while blue lines illustrate inverse expression relationships. Genes with a yellow border are annotated with significantly over-represented GO Biological Process categories (Figures 2 and 4). The shapes illustrate the membership of those genes in different families of ECM components among those listed in the online supplementary table 1 and the Additional file 2.