We investigated the cytotoxic effects of combination treatment with Ref‐1 inhibitors and Rux or Napa using a proliferation‐based assay in multiple human cancer cell lines, including malignant peripheral nerve sheath tumour (MPNST), bladder, colon and glioblastoma, as well as three mouse pancreatic cancer cell lines established from KPC mice (Figure 1, Figure S1). Here, APEX1 is linked to cancer.