Two categories of colorectal tumor cell lines were chosen: (1) the human epithelial colon cancer cell line HCT116 that was previously characterized to have a relatively stable genome (CIN−cells, the HCT116 cell line has two wild-type APC alleles, is near-diploid, is chromosomally stable and has a robust spindle checkpoint37) and (2) the SW480 cell line that was previously characterized to have high rates of CIN (CIN+ cells; SW480, this cell line expresses a truncated APC version, N1338 and a wild-type APC protein38,39). The gene discussed is APC; the disease is colorectal neoplasm.