Methionine metabolism gene expression is increased in the cerebral cortex of cyclo-oxygenase (COX)-2-/- mice. The expression of two tandem genes involved in the metabolism of methionine to homocysteine is increased in the cortex of COX-2-/- mice, as determined by microarray and quantitative PCR (Q-PCR) analysis. These genes, namely methionine adenosyltransferase (MAT2B) and S-adenosylhomocysteine hydrolase (AHCY), are depicted in the ovals above, along with the enzyme classification (EC) number in parenthesis. Z ratio from the microarray analysis and Q-PCR validation results for each gene are provided below the name of the gene. A positive z ratio represents an increase in expression in COX knockout mice, whereas a negative value denotes a decrease in expression in COX knockout mice. Q-PCR percentage represents the percentage increase in expression over wild-type mice.