ATG5 and obstructive sleep apnea syndrome: We speculate that hypermethylated LC3B gene promoter and hypomethylated p62 gene promoter may be inheritable epigenotypes responsible for susceptibility to OSA and its adverse consequences through impairing autophagy activity, while hypermethylated ATG5 gene promoter regions may contribute to morning headache or subjective memory impairment in OSA patients in response to chronic intermittent hypoxia exposure.