Breast cancer. Immunofluorescent light micrograph of cultured human breast cancer cells. Round nuclei of individual cells are stained blue. Red grains around the cytoplasm of the cell are phosphotyrosine protein particles. This protein helps cells to attach to one another, it also helps the cell to sense" it's own environment. Other proteins within the cell are stained green and yellow. Immunofluorescence is a staining technique which uses antibodies to attach fluorescent dyes to specific molecules within cells. Magnification: x374 at 6x4.5cm size."