PTGS1 and obstructive sleep apnea syndrome: In the validation cohort, PTGS1 (COX1) gene expression was increased in treatment-naïve OSA (18.1 ± 30.7 fold change, Figure 5G) versus either PS (1.6 ± 2.3 fold change, adjusted p = 0.007) or OSA on CPAP (5.4 ± 5.9-fold change, adjusted p = 0.024) group.