Errors in mitosis can cause cancer by creating changes in our cells. Mitosis is the process where cells divide to make new cells. During this division, it's important that each new cell gets a correct set of genetic instructions. But sometimes, mistakes happen. Here are a few ways those mistakes can lead to problems:

1. Aneuploidy: This happens when a cell ends up with too many or too few chromosomes. For example, if a cell gets an extra copy of chromosome 21, it can lead to Down syndrome. In cancer, having the wrong number of chromosomes can make cells grow out of control.

2. Chromosomal Translocations: Sometimes, pieces of chromosomes can break off and join together in the wrong way. This can turn on genes that make cells grow too fast, leading to cancer. A well-known example is the Philadelphia chromosome, which is found in people with chronic myeloid leukemia.

3. Mitotic Spindle Errors: The mitotic spindle is like a set of ropes that helps move chromosomes during cell division. If it doesn't work properly, chromosomes can be pulled apart incorrectly. This can cause messy division of the cell.

All these errors can add up and change normal cells into cancer cells.