Why cluster? Cluster genes(rows) Measure expression at multiple time-points, different conditions etc Similar expression patterns may suggest similar functions ot genes Cluster samples(columns) e.g., expression levels of thousands of genes for each tumor sample Similar expression patterns may suggest biological relationship among samplesWhy cluster? • Cluster genes (rows) – Measure expression at multiple time-points, different conditions, etc. – Similar expression patterns may suggest similar functions of genes • Cluster samples (columns) – e.g., expression levels of thousands of genes for each tumor sample – Similar expression patterns may suggest biological relationship among samples