Surplus chromosomes may fuel tumor growth in some cancers
Without that extra genetic material, cancerous cells form fewer tumors in mice
![chromosome](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2019/12/121219_ti_cancer-addiction_feat.jpg?fit=1028%2C579&ssl=1)
Mistakes that happen as cells replicate their DNA, repair broken DNA or divide into two cells can result in an extra or missing copy of a chromosome. In this microscope image, one chromosome (green) lags behind as a HeLa cancer cell divides.
Iain M. Porter/Univ. of Dundee, Wellcome Images (CC BY-NC-ND 3.0)