The number of genes identified in GO Molecular Function terms (more specifically, the first level children of molecular function). The bars are annotated with the number of SGD genes annotated in that term and the number of SGD genes seen in PeptideAtlas for that term. Many annotated as unknown are present in the PeptideAtlas.
King et al. Genome Biology 2006 7:R106 doi:10.1186/gb-2006-7-11-r106