Doctors are a step closer to finding a drug that could stop one of the most aggressive forms of breast cancer from growing.
Britain's Institute of Cancer Research has discovered how and where a form of breast cancer known as "triple negative" develops.
Sam Hills was one of 9,000 women who are diagnosed each year with "triple negative" breast cancer.
She was pregnant at the time with son Harvey, who is now a healthy four-year-old.
She didn't realize then, but she had one form of cancer that was very difficult to treat.
Breast cancer is normally diagnosed by the presence or lack of three receptors which fuel them, the hormones estrogen and progesterone and the protein HER2.
Drugs target these receptors. But "triple negative" tumors don't have these receptors.
Instead, they come from cells called progenitors which are not fully functional, hence the lack of response from targeted drugs.
But new research in this west London laboratory has identified the source of "triple negative" breast cancer, which makes the possibility of targeted drugs that much closer.
"It's a fundamental breakthrough of our understanding of the disease. We think this will lead to new treatments basically designed to tackle the specific aspects of the biology of this specific type of aggressive tumor," said Dr. Matt Smalley.
For women like Sam Hills, it could be a lifeline.
"I felt like I had a ticking time bomb. I've been extraordinarily lucky," said Sam. "My treatments worked really well, here I am with a four-and-a-half-year-old child. Everything looks like I'm going to be fine, but I certainly didn't feel that at the time, so for me to hear there are developments in 'triple negative' breast cancer treatment is fantastic. Hopefully there will be more women like myself who are fine four and a half years down the line, and less people like friends of mine who unfortunately didn't make it."
But doctors warn new drugs could be three or even four years away.