CD63 and Dravet syndrome: We also studied the levels of these proteins in cell lysates and found that the expression levels of CD63 (DS/2N ratio = 2.30, p = 0.0016) and rab35 (DS/2N ratio = 1.56, p = 0.024) were higher in DS than in 2N fibroblasts (Fig. 4b), consistent with the observation in DS postmortem brain (Fig. 3a).