The error-free duplication of a multicelled organism’s genetic material is critical to its survival. Even small changes in the genetic code during duplication can lead to diseases such as cancer. Equally important to cell division is the error-free transmission of chromosomes to each of the two daughter cells, which depends on the proper regulation of sister chromatid cohesion (the attachment of both strands of newly-replicated DNA to the area of the chromosome called the centromere). When the mechanisms involved in chromatid cohesion are defective, there may be uneven segregation of chromosomes to daughter cells. This results in abnormal chromosome numbers (aneuploidy), a characteristic of many cancers. Ben Montpetit is studying the components responsible for regulating cohesion of sister chromatids. Ben’s research is aimed at providing a better understanding of what happens when the cohesion process is flawed, and to help identify therapeutic targets in cells with defects due to altered chromatid cohesion.