For many pairs of bait and prey genes, yeast protein-protein interactions were tested in an unbiased fashion using a high saturation,high-stringency variant of the yeast two-hybrid (Y2H) method. A high confidence subset of gene pairs that were found to interact in at least threerepetitions of the experiment but that hadn’t been reported in the literature was extracted. There were 47 yeast genes involved in these pairs.Including self interactions, there are a tot”al of 47*48/2 possible pairs of genes that can be formed with these 47 genes. As mentioned abovesome of these gene pairs were seen to consistently interact in at least three repetitions of the Y2H experiments: these gene pairs form the “goldstandard positive” set. A second set among these gene pairs were seen never to interact in repeated experiments and were not reported asinteracting in the literature; we call this the “gold standard negative” set. Finally in a third set of gene pairs, which we shall call the “undecided”set, genes were seen to interact only once or twice in repeated experiments, or were seen never to interact but were reported as interacting inthe literature. The challenge consists of predicting which gene pairs belong to the gold standard positive set, and which gene pairs belong to thegold standard negative set. More info