In a second targeting step we edited the newly formed genomic site with a specific sgRNA spanning the new junction (−1462 to +67) to reinsert and restore the deleted region with either the wild-type promoter or an altered region containing the most frequent cancer-associated TERT promoter mutations: −57A/C, −124C/T, or −146C/T (Figure 1B). The gene discussed is TERT; the disease is cancer.