How does gene expression clustering work?

Abstract

Clustering is often one of the first steps in gene expression analysis. How do clustering algorithms work, which ones should we use and what can we expect from them? Our ability to gather genome-wide expression data has far outstripped the ability of our puny human brains to process the raw data. We can distill the data down to a more comprehensible level by subdividing the genes into a smaller number of categories and then analyzing those.