Protein kinases catalyze the transfer of high energy phosphate groups to variety of substrates including peptide/proteins, lipids, carbohydrates and nucleic acids. This conversion generally results in a significant change in conformation or activity of the receptor molecule. A number of processes may be affected including cell motility, transcription, signaling and transport. Cell biology and the underlying pathology of many diseases may be linked to the inherent activity or expression of protein kinases. Thus quantitation of the amount or activity of each kinase has the potential to yield information regarding the pathways underlying a particular phenotype. The human kinase library contains primer sets for over 350 kinases and offers the opportunity to use quantitative real time PCR arrays to identify changes in kinase gene expression.