Dense breasts are really important for a couple of reasons. Number one, dense breasts actually increases the risk of having breast cancer; and number two, that dense tissue can hide cancers. Dense tissue is white on a mammogram, and cancers are white. So as a radiologist, I'm trying to find that white cancer in white tissue-- that's really hard. And so it depends how white the tissue is, but it can-- what we call-- mask the cancers. So we know that the sensitivity of mammography is significantly lower for women with dense tissue compared to women with fatty tissue. So we find about 70% of breast cancers in women with fatty tissue are early-- only about 50% in women with dense tissue. Women with really dense tissue should consider getting other imaging-- and by that, mainly I would recommend a screening breast ultrasound. We have a really easy way to do that at our screening site, which is Northridge. We have an automated 3D ultrasound machine, so you can have your mammogram and your ultrasound at the same appointment. By adding ultrasound, we can detect 30% more breast cancers, and they're almost always invasive cancers, but they're small typically. So that's where we want to find cancers-- when they're small, they're much easier to treat and take care of. So by adding those two together, it really improves our ability to detect early cancer in women with dense tissue.