Discriminating among validated and not validated BAR+ clusters. The number of clusters containing GO terms of three main roots and Pfam terms is reported as a function of the Bonferroni-corrected P-value. The black vertical line sets the boundary among validated and not validated terms. It can be proven (data not shown) that that a P-value ≤ 0.01 is a discriminative value good enough to discriminate among the real and the random distribution of each type of GO and Pfam terms (for mathematical details see . Green colour: Pfam terms; Blue colour: Molecular Function (MFO); Red colour: Biological Process (BPO); Pale blue: Cellular Component (CCO). For the different curves the number of validated clusters as compared to the total number of BAR+ clusters is: Pfam 197,826/455,309; MFO 84,506/321,748; BPO 75,147/265,164; CCO 31,042/145,677. The total number of cluster with at least a GO validated term is 100,791.