The news hit the internet Monday evening that Angelina Jolie recently underwent a double mastectomy. The actress lost her own mother to breast cancer and learned that she's carrying the gene that exponentially increases her own chance of getting the disease. More from Angelina's New York Times op-ed under the cut.

...I carry a “faulty” gene, BRCA1, which sharply increases my risk of developing breast cancer and ovarian cancer.
My doctors estimated that I had an 87 percent risk of breast cancer and a 50 percent risk of ovarian cancer, although the risk is different in the case of each woman.

Only a fraction of breast cancers result from an inherited gene mutation. Those with a defect in BRCA1 have a 65 percent risk of getting it, on average.

Once I knew that this was my reality, I decided to be proactive and to minimize the risk as much I could. I made a decision to have a preventive double mastectomy. I started with the breasts, as my risk of breast cancer is higher than my risk of ovarian cancer, and the surgery is more complex.

Since having the surgery, Angelina's chances of developing breast cancer have dropped to under 5 percent