Many risk factors can increase your chance of
developing breast cancer, but it is not yet
known exactly how some of these risk factors
cause cells to become cancerous.
Hormones seem to play a role in many cases of
breast cancer, but just how this happens is not
fully understood.
DNA is the chemical in each of our cells that
makes up our genes—the instructions for how our cells function. We usually
look like our parents because they are the source of our DNA. But DNA
affects more than how we look.