I've been intrigued and privileged to manage sun-induced conditions for a number of years, melanomas, which I've heard my colleagues speak about, which are clearly influenced by the sun; and non-melanoma conditions, the ones that most people have. I'd also just mention that there are some conditions that are very photo-sensitive. Lupus erythematosus, for example, is very sensitive to the sun, and you'd be wanting people with that to be using sunblock as well, but the cancers are the main lesions that we want to be attending to. And, of course, these talk to the properties of UVB, and the more ubiquitous rays and then the less defined UVA, and I'll talk about that a little bit further when we get into the sunblocks. 