Human papillomavirus (HPV), primarily HPV 16 & 18, are strongly implicated in the development of squamous cell carcinoma of the penis. Three carcinoma in situ are associated with squamous cell carcinoma of the penis: 1) Bowen's disease which presents as leukoplakia on the shaft. Around 1/3 progress to squamous cell carcinoma
The innate immune system is the bodyâs first line of defense against infection by microorganisms such as viruses, bacteria, and parasites.
Innate Immunity. 1  Mechanical barriers include the skin and membranes that line our mouths, nose, airways, urinary tracts, and gastrointestinal organs. When these are intact, they provide a physical barrier against the entry of toxins and harmful organisms.