In the December Nature Biotechnology Schwikowski et al. combine the large-scale two-hybrid analyses of Uetz et al. and Ito et al. with other published two-hybrid results to come up with a total of 2,709 interactions encompassing 2,039 different yeast proteins. The synthesis of these results yields a single large network of 2,358 interactions among 1,548 yeast proteins, with the next largest network containing only 19 proteins (Nat Biotechnol 2000, 18:1257-1261). Connections between proteins assigned to different functional groups suggests, for example, that protein folding and translocation are related, as are RNA processing and translation. The connections can also be used to determine the function of uncharacterized proteins, with multiple connections to one process strengthening the case. There are, however, only 364 yeast proteins of unknown function that have at least one partner of known function, and only 69 with two or more partners of known...