The downregulation was slower than the upregulation response (3 of 370 downregulated genes significant after 24 h, versus 70 (35%) of 198 upregulated genes; Supplementary Fig. 3) and included both BRCA genes, the BRCA interactors BRIP1 and BARD1, RAD51, several E2F transcription factors (E2F1, E2F2, E2F8), TOP2A, MKI67, cyclins (e.g. CCNA2 and CCNB1/2), the cyclin-regulating gene FOXM1, MCM4/5/6/10 and genes from the Fanconi anaemia complementation group (FANCD2, FANCB, FANCI; Fig. 3b, c and Supplementary Dataset 1). This evidence concerns the gene RAD51 and Fanconi anemia.