Microarray studies of the placenta have identified a number of mitochondrial genes are altered in the presence of maternal asthma during pregnancy in both males and females [22] including ATP synthase 2B4 (ATP2B4), cytochrome p450 (CYP19A1), catechol-O-methyltransferase (COMT), coproporphyrinogen oxidase (CPOX), and malate dehydrogenase 2 (MDH2). This evidence concerns the gene CPOX and asthma.