CD38 and Anxiety: Several other mechanisms have also been postulated to cause a reduction in OT release, such as reduced OT levels due to CD38 mutation (Jin et al., 2007), abnormalities in OT prohormone processing (Green et al., 2001), as well as OTR abnormalities and reduction in the stimulation of endogenous secretion in response to positive events such as parental touch or negative events such as anxiety (Feldman et al., 2012; Taurines et al., 2014; Watanabe et al., 2017).