A cell-based potency assay was developed for onabotulinumtoxinA (Botox, Allergan Inc., Dublin, Ireland) that utilizes differentiated human neuroblastoma SiMa cells and a sandwich enzyme-linked immunosorbent assay readout, which measures BoNT-A-dependent intracellular increase of cleaved SNAP-25 [23]. This evidence concerns the gene SNAP25 and neuroblastoma.