Warts are small lumps that often develop on the hands or feet, according to the NHS. They’re caused by the human papilloma virus (HPV) infection, and are more likely to affect children and teenagers ...
Strauss, M. J., Shaw, E. W., Bunting, H., and Melnick, J. L., Proc. Soc. Exp. Biol. and Med., 72, 46 (1949).