NFIL3 and delirium: This is in line with the clinical observation that delirium symptoms tend to be worse at night (rest phase for humans).[53] The time‐varying severity of delirium in mice is well explained by the circadian expression of hippocampal E4bp4 (as a delirium‐inhibiting gene) with lower expression during the rest period and higher expression during the activity period (Figures 1K and 3).