A recent study has discovered that the gene-editing tool Crispr-Cas9 can cause unwanted modifications in human embryos. Crispr-Cas9 is a scissor-like chemical tool that precisely cuts and customizes genetic material (Wu, 2020) The tool is already used to treat conditions such as blindness. However, modifications made to gametes could be passed to future generations which would increase the risk for any mistakes present (Wu, 2020). Although the purpose of Crispr-Cas9 is to address genetic mutations, the machinery resulted in some cells losing entire chromosomes. In a study with donated sperm with a mutation EYS, the genetic damage in some embryos failed to heal (Wu, 2020). The safety concerns of using this tool in human embryos remains controversial as the US interdicts federal funds to be used in research of testing human embryos as it is deemed unethical (Ledford, 2020).