RELN and major depressive disorder: This suggests that reelin may have a peripheral effect on lymphocytes that is not observed in ketamine, and could be an idea worth pursuing (i.e. the peripheral effects of reelin) when considering that similar alterations to those induced by CORT in SERT-clusters have been observed in naive depression patients, and were considered to represent a putative biomarker of therapeutic efficacy of antidepressant medication (Rivera-Baltanas et al., 2012; Rivera-Baltanas et al., 2015; Caruncho et al., 2019).