We next adapted this strategy to neuroblastoma SH-SY5Y cells using transduction with dCas9-TET1 + gRNA2 + gRNA3 lentiviruses (Fig. 4e) and could confirm the editing efficiency in these cells with 15-35% decrease of DNA methylation spanning throughout CpGs 1–3 (Fig. 4f). The gene discussed is TET1; the disease is neuroblastoma.