In the HO-2 null mouse, the incidence of OSA is absent with co-inhibition of CSE Peng et al., 2018, which is consistent with reports that CO generated by HO-2 inhibits CSE-dependent H2S production Prabhakar, 2012; Morikawa et al., 2012. Here, HMOX2 is linked to obstructive sleep apnea syndrome.