Comparison of experimentally confirmed HGRs with those predicted by NetOGlyc (pHGRs) and with Ser/Thr-rich regions in the same set of proteins. A: Experimental HGRs are represented as green boxes and pHGRs as red boxes. Ser/Thr-rich regions are represented as blue boxes. HGRs have a minimum of 15% O-glycosylated residues in the case of the experimental data, or 25% in the case of NetOGlyc-predicted O-glycosylation sites (to correct for the overestimation produced by NetOGlyc). Ser/Thr rich regions have a minimum Ser/Thr content of 40%. Numbers in brackets identify these proteins in Additional file 1, with more information for each of them including references. B: Venn diagram displaying the number of amino acid coincidences in the three kinds of regions. Each area is proportional to the number of amino acids (also displayed in the figure) which are inside a given type of region (or in several of them simultaneously) for the whole protein set.