HDAC1 and obstructive sleep apnea syndrome: HDAC1 gene expression was increased in OSA patients with severe excessive daytime sleepiness (EDS) (n = 15, ESS > 14; 3.28 ± 3.31 fold change; Fig. 2G) versus those without severe EDS (n = 41; 1.63 ± 1.72 fold change, p = 0.014/adjusted p = 0.019) or PS subjects (1.09 ± 0.88 fold change, p = 0.01/adjusted p = 0.019).