HTR4 and Dravet syndrome: Studies with the repurposed drug and antiseizure medication (ASM) fenfluramine—a potent serotonin releaser with positive modulatory activity at Sigma‐1 receptors and agonist activity at 5‐HT receptors (5‐HT2, with additional evidence for 5‐HT1D and 5‐HT4)8, 9—have demonstrated decreased seizure frequency in patients with DEEs, including Dravet syndrome (DS), Lennox–Gastaut syndrome (LGS), Sunflower syndrome, and CDKL deficiency disease (CDD).8, 10, 11, 12