Interestingly, we found that LBCs carrying a Del or Dup of 1q21.1 failed to arrest in G2 following Topo II inhibition, and instead, exhibited elevated pseudomitosis similar to WRN-defective cells from a patient with Werner syndrome (OMIM #277700, Figure 3D), which are known to exhibit defective DCC activation [29]. This evidence concerns the gene DCC and Werner syndrome.