CLOCK and insomnia: There are some studies reported that acupuncture treatment with acupoints combination can upregulate the expression of circadian rhythm genes of Clock and Bmal1 in the hypothalamus (Wei et al., 2017) and the circadian rhythm genes of Per1 and Per2 in the suprachiasmatic nucleus (SCN) in insomnia rats (Guo et al., 2017), while some other research group reported that electroacupuncture treatment down-regulated the expression of Per1 and Per2 in the SCN (Hou et al., 2018).