Cancer cells. Immunofluorescent light micrograph of a population of epithelial cells, some of which are cancerous (blue). The colours show different cell proteins marked by fluorescent dyes. Blue is DNA (deoxyribonucleic acid), the cellular genetic material. Red is the actin cytoskeleton. Green is E-Cadherin, as epithelial adhesion molecule. The normal cells have a lot of E-Cadherin, while the carcinoma (cancerous) cells do not and appear blue rather than green. The yellow colour shows overlap between actin and E-Cadherin.