 By examining skin cancer in mice, she concluded that the speed at which stem cells will divide and how they divide is dependent on their niche.She examined the inhibitory signaling molecule, TGF-β, which is found near the blood vessels of a tumor.Although the effects of TGF-β and how it restrains normal skin cell growth had been studied by researchers before Fuchs, she specifically looked at the intermediate steps of tumor progression by creating a TGF-β reporter system.