Intriguingly, for the cohort of patients with SDB, ACE2 expression was significantly decreased in women (to 2.7 ± 0.2) compared to men (4.0 ± 0.4, P = 0.005), and there was a strong trend compared to women without SDB (5.3 ± 1.4, P = 0.063, Figure 2E). Here, ACE2 is linked to sleep apnea syndrome.