Figure 2.

CIN drives ongoing karyotypic heterogeneity within cellular populations. A schematic depicting a hypothetical example of CIN within an initial cell that for illustrative purposes contains only three pairs of chromosomes (i.e., a partial karyotype). As this cell undergoes two rounds of cellular division, chromosomes are gained or lost, producing a heterogeneous population of genetically distinct daughter cells, which is referred to as intratumoral heterogeneity in a cancer context. Some karyotypic changes may not be compatible with cell viability, as indicated by the orange cell which is lost from the population. Note that while this example focuses on small-scale gains/losses of whole chromosomes (N-CIN), chromosome complements may also evolve via increases in ploidy (N-CIN) or structural chromosome changes (S-CIN) (see Figure 1), and often include a combination of both N- and S-CIN.