Figure 1.

Boolean implication in gene expression database. Boolean implication is a pair-wise gene expression relationship between two genes with respect to their gene expression values. (A) Schematic example of a Boolean implication between two genes A and B. Threshold to separate high and low gene expression values are computed using StepMiner. A noise margin of 0.5 is used for statistical calculations. Each of the four quadrant is tested for their sparsity. In this case, A high and B low quadrant is sparse representing the Boolean implication “if A high, then B high.” (B) An example of a significant Boolean implication between ESR1 and CD9: if ESR1 high, then CD9 high. Every point is a microarray experiment performed on human samples on Affymetrix platform. There are 46,045 microarrays in this scatter plot all of which were downloaded from NCBI’s Gene Expression Omnibus (GEO) website.