Functional Genomics, a branch of Bioinformatics, is essentially an interdisciplinary subject in which Biologists, Statisticians and Computer experts interact to analyze the microarray data. This book caters to the needs of all the three disciplines. For Biologists and Computer scientists, it explains concepts of statistics and statistical inference. For Biologists and Statisticians, it provides annotated R programs to analyze microarray data. For Statisticians and Computer scientists, it explains basics of biology relevant to microarray experiment. Thus, the book will be useful to scientists from all the three disciplines, with not much knowledge of other disciplines, to analyze microarray data and interpret the results.