And so through these two mechanisms, the chance of surviving has improved.

I do think that breast cancer is one of the areas where we really have unequivocal evidence from my perspective that mammography can have an impact.

We have half a dozen randomized trials that have been done over a long period of time that suggest that there's an impact.

I think the challenge for consumers, people like me, is that the guidelines have shifted over time as we learn more going along.

And you're right that the guidelines are not ironclad.

different groups might have different recommendations about how people should proceed.

But I think that the current thinking would be, first of all, Derek, that we're a lot less focused right now on breast self-exam than we used to be.

Can you tell us a little bit more about the role of advocacy? What have been the positives and what are some of the points of friction?