The criteria for considering a wound biopsy in a given patient are a chronic wound (venous leg ulcer, diabetic foot ulcer, decubitus ulcer) that has been present for over two (2) months and has failed to progress towards healing (less than 20% decrease in size over 2-week period of time). Also any suspicious wound in which cancer is strongly considered on a clinical basis should be biopsied immediately without any arbitrary timeline being imposed.