Intracellular FPR3 expression of NK cell was significantly decreased in PS (2.1±0.4 MFI, p<0.001/adjusted p<0.001), treatment-naive OSA (2.28±0.43 MFI, P<0.001/adjusted p = 0.006), and severe OSA on CPAP (2.15±0.39 MFI, p<0.001/adjusted p<0.001) groups as compared with that in HS (2.94±0.58 MFI) group (Fig 2F). This evidence concerns the gene FPR3 and obstructive sleep apnea syndrome.