Dysfunction of the circadian rhythm clock promoted progression of COPD within the lung, via inflammatory and oxidative stress responses, leading to worsened symptoms and severity of the disease in the early morning or late night including reduced lung function (Scichilone et al., 2019; Tsai et al., 2019), nocturnal oxygen desaturation (McNicholas et al., 2013) and cardiac arrhythmias (McNicholas et al., 2013). This evidence concerns the gene CLOCK and chronic obstructive pulmonary disease.