In order to evaluate the role of WRN in cancer resistance to TOP1cc, WRN expression was abolished in U2‐OS osteosarcoma by CRISPR‐Cas9 double nickase system (WRN‐KO vs. WRN‐WT cells expressing control CRISPR‐Cas9 double nickase vector; Figure S3a). The gene discussed is WRN; the disease is osteosarcoma.