1. An evaluation system comprising: a capture unit that captures an image of a living tissue in which HER2 protein and cell nucleuses are dyed; a discrimination unit that identifies a cell membrane from the image of the living tissue based on dyed cell nucleuses within the image of the living tissue captured by said capture unit to discriminate a dyed state of the cell membrane; and an evaluation unit that evaluates development of the HER2 protein based on a discrimination result by said discrimination unit.