Fig. 1

An illustration of how we define the “database validation through PPI rediscovery” approach. The rectangle area consisting of both the S set (in green shades) and the T set (in red shades) represents all genes taken from a curated gene set x from the MSigDB database. The lines connecting genes are PPIs all taken from a single database under validation. The G set shows new (“discovered”, outside of the rectangle) or old genes (“re-discovered”, in either the S set or the T set) by expanding from genes in the S set by one layer of PPI relationships