This document discusses analyzing cell cycle microarray data. It mentions that microarrays allow measuring RNA levels of all genes at once using two technologies: mechanical spotting of cDNAs/ESTs/oligomer probes or photolithography using Affymetrix chips. The document discusses normalizing the data and examples of real-world cell cycle expression studies that analyzed synchronized cell cultures over time courses using microarrays and identified periodically expressed genes through various computational methods like Fourier analysis, pattern matching, and statistical tests.