Inhibitors for the endoprotease furin are provided for the prevention, diagnosis, treatment, and study of human and animal pathologies, which involve furin activity. These pathologies include infections caused by bacteria and virus that exploit host furin activity. These pathologies also include diseases that involve the expression of host proproteins that are processed by furin as a part of growth, development, and maintenance of the host organism including certain cancers of the head and neck.