semen analysis, you look at the percent modal, and that should be about 50% or more, so in other words, it's normal for a guy's sperm counts to have only about 50% of them moving because we're so constantly turning over sperm. We're making millions and millions of sperm every day, and millions and millions of sperm every day are turning over, so 50%, greater--normal. We also then look at how fast the fast guys are moving. That's what we call the progressive motility because, again, that changes how we approach things. If you have a man .