The significance of this result in the context of the heightened levels of ROS in the inflamed asthmatic or COPD-diseased lung may imply that under these conditions, β2AR is exposed to conditions that favor higher order oxidation of cysteine residues, namely Cys-S-sulfinic or Cys-S-sulfonic acids. Here, ADRB2 is linked to chronic obstructive pulmonary disease.