A) NSCLC lines in which pRB function is compromised were treated with siRNA constructs targeting Wapl, or alternatively with a scrambled control for 36 h, fixed, stained (tubulin, ACA (kinet), and DAPI) and assessed for anaphase defects. Each NSCLC line analyzed exhibited massive segregation defects, including the presence of single and numerous lagging chromosomes and DNA bridges (representative images in panel A; arrow heads indicate kinetochores of lagging chromosomes). B) Wapl depletion suppressed the incidence of lagging chromosomes in each cell line.