Liquid Association Pairs

Introduction

Correlation is a simple and powerful method for analyzing gene expression data.Two genes with positively correlated expression profiles are likely to be functionally associated. They may participate in the same biological process. However, functionally associated genes may not be correlated for a variety of reasons. For instance, they may not be regulated at the transcription level. Another common situation is that most genes have multiple functions. Depending on the cellular needs, co-expressed genes may become uncorrelated or even turn into contra-expressed. Liquid association (LA), as opposed to "steady" association, is designed to quantify the change of correlation between two genes as a relevant cellular state variable changes. There is no need to specify the state variable explicitly.

The method works under the assumption that the state variable is associated with other gene expression profiles or with some external variables. One basic way of applying LA is to set X = name of gene A, Y= name of gene B, Z= any gene. The computer will search the database and find a small set of genes Z that are mostly influential in altering the correlation pattern between genes A and B. Several computation options are allowed.