The new study included 21 healthy volunteers with sun-damaged skin and actinic keratoses -- skin lesions that could develop into skin cancer -- on their faces.

• 该项研究是针对21位志愿者展开的，他们脸部的皮肤均被晒伤且患有光化性角化病-一种可演变为皮肤癌的皮肤损害。