许多癌在开始时并非是致命的，而转移癌细胞通常是真正的杀伤细胞。癌细胞的转移，即其进入血管以及再穿出血管进入其它组织，必须穿过细胞层以及环绕在细胞层外的稠密的基质。细胞外基质中有大量硫酸类肝素，它是一种复合糖，可以封阻癌细胞的移动。大约２０年前，科学家证明 Many cancers are not fatal at the beginning, and metastatic cancer cells are usually true killer cells. The metastasis of cancer cells, that is, their entry into blood vessels and their re-explantation of blood vessels into other tissues, must pass through the cell layer and the dense matrix that surrounds the cell layer. There is a large amount of heparan sulfate in the extracellular matrix, which is a complex carbohydrate that blocks the movement of cancer cells. About 20 years ago, scientists proved