Hello. Plantar warts are caused by virus infection, the virus is named HPV. The warts are not cancerous though, they're not harmful. There are OTC wart removal products available, they work for like 50 percent of the cases. Some people may use tea tree oil or apple cider vinegar as a home remedy. You may also get support from your health provider, a laser or surgery can remove them all. However, even if you let them be, they'll disappear one day thanks to the immune system.