In the current study, we demonstrate that introduction of the activated H-RasV12 GTPase into immortalized bronchial epithelial cells increases COX Vb protein expression, COX activity and oxygen consumption and that COX Vb protein expression is required to maintain the high oxygen consumption and ATP concentration of A549 lung adenocarcinoma cells that express oncogenic K-Ras. This evidence concerns the gene COX5B and lung adenocarcinoma.