Notes: PFM01 is an inhibitor of the endonuclease activity of the double-strand break repair protein Mre11.{61915} It decreases the number of chromosomal breaks in 1BR3 fibroblasts induced by knockdown of BRCA2. PFM01 (50 µM) reduces homologous recombination-mediated DNA repair in DR-GFP U2OS cells and enhances DNA repair mediated by non-homologous end-joining (NHEJ) in H1299 dA3 cells.