FGF21 and Dravet syndrome: When comparing among 22 DS patients, mean of log10 FGF‐21 level was significantly higher in DS patients with normal‐to‐mild ID (Mean ± SEM: 2.734 ± 0.2261; n = 13) comparing with those with moderate to severe ID (Mean ± SEM: 1.766 ± 0.3138; n = 8) by unpaired t‐test (two‐tailed P value = .0193) (Figure 2A).