Network analysis and protein class enrichment of housekeeping and tissue-specific genes. A. Average connectivity of global protein interaction, housekeeping (HK) and several tissue-specific gene sets. B. Protein class enrichment analysis. The actual (black or blue bars) and expected (open red box) number of transcription factors (first bar), receptors (second bar) and enzymes (third bar) for each tissue. The blue bars correspond to HK proteins. The circles identify several tissues enriched in transcriptional factors (blue), receptors (green) and enzymes (red). C. Network component enrichment analysis. The upper part of the figure shows the schematic illustration of IN, OUT and GSC (figure adopted from Brodel et al. ). The lower panel shows the actual (black and blue bars) and expected (open red boxes) number of genes in the GSC (first), IN (second) and OUT (third) components. The blue bars correspond to housekeeping proteins. The circles identify several tissues enriched in GSC proteins (red), IN proteins (green) and OUT (blue).