A team of Chinese scientists has achieved for the first time that genetically modified silkworms make spider silk thread. Spider silk thread is also six times stronger than Kevlar, the synthetic fibre used to make bulletproof vests. Researchers used CRISPR-Cas9 gene-editing technology and hundreds of thousands of microinjections into fertilized silkworm eggs to modify the worms' DNA and introduce spider genes to it. Currently, worm silk is the only animal silk fiber marketed on a large scale.