Throughout history, people have attributed warts to contact with things like sea foam, boiled egg water, and, of course, toads.
纵观历史，人们将皮肤疣归因于接触了海沫、煮鸡蛋水，当然还有蟾蜍等物质。
We now know that toads are totally innocent in the matter.
我们现在知道，在这件事上，蟾蜍完全是无辜的。
They're bumpy because mucus- and poison-secreting glands dot their skin.
它们皮肤纹理凹凸不平是因为上面布满了分泌粘液和毒液的腺体。
And we've figured out that warts are actually caused by papillomaviruses.
我们发现疣实际上是由乳头瘤病毒引起的。
They form a broad virus family that infects various species, including us.
乳头瘤病毒建立了一个庞大的病毒家族，感染各种物种，包括人类。
There are more than 200 different types of specifically human papillomaviruses, or HPVs.
As is the case with all viruses, HPVs can't multiply independently.
Instead, HPVs use our skin cells to replicate.
They do this by infecting the basal cells that constantly produce new skin cells and line the base of our skin's outermost layer, the epidermis.
Your skin is your largest organ.
