Lung cancer cells. Immunofluorescent light micrograph of a culture of multidrug-resistant lung cancer cells. Cancer cells are cells that proliferate in a disorganized, uncontrolled manner. Here, the cells have been treated with ribonuclease (RNAase). This enzyme assists in the breakdown of RNA (ribonucleic acid). The cell nuclei (blue) contain regions of phosphoproteins (pink). The cytoplasmic web-like pattern (green) represents a nuclear matrix protein relocalized by the RNAase treatment. Immunofluorescence is a technique using antibodies to attach fluorescent dyes to cells. Magnification: x624 at 6x4.5cm size.