However, given that TCF4 expression in humans peaks in the prenatal period and thendecreases to the baseline level maintained throughout life(Rannals et al., 2016; Phan et al., 2020), the question arisesabout the possibility of restoring physiological and behavioralfunctions of patients with PTHS by normalizing TCF4 expressionin the postnatal period. This evidence concerns the gene TCF4 and Pitt-Hopkins syndrome.