We did not see preferential killing of MLH1-deficient vs MLH1-proficient colon cancer cells (HCT116) or fibroblasts (M1) using DPQ and MNU, as has been reported using temozolomide and second-generation PARP inhibitors such as AG14361 (Curtin et al, 2004) or NU1025 (Tentori et al, 1999). This evidence concerns the gene PARP1 and malignant colon neoplasm.