To do so, Dr Tsien took advantage of enzymes called matrix metalloproteinases (MMPs), which cancer cells use to chew their way through connective tissue and other material.

• 为了达到这个目标，钱博士利用了一种叫做基质金属蛋白酶的酶。癌细胞用这种酶来开辟通过结缔组织和其他物质的通道。