Throughout history, people have attributed warts to contact with things like sea foam, boiled egg water, and, of course, toads.
We now know that toads are totally innocent in the matter.
They're bumpy because mucus- and poison-secreting glands dot their skin.
And we've figured out that warts are actually caused by papillomaviruses.
They form a broad virus family that infects various species, including us.
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.
