Cell cycle analysis with BLM or Topo IIIα depletion. Cells with or without MMC (80 ng/ml) were analyzed for DNA content. Cells are GM639 (normal) with control siRNA (A, B), GM08505 (BS) (C, D), GM639 with Topo IIIα siRNA (E, F), and GM6914 (FANCA) (G, H).