We focus on the research of placental development process, and have established mouse haTSCs. Here, we try to establish human haploid TSCs, which are further used in genetic screening of placental development process. Haploid cells are excellent in recessive traits due to their single genome feature without allelic gene mask and piggyBac (PB) transposon is one of the most used strategy to induce mutations. By using PB mutagenesis in human haploid TSCs, thousands of homozygous gene could be derived. Thereafter, candidate genes affecting placental development could be selected out through chimeric producing experiment. Through comparing candidate genes with previous reported genes, we choose high scored genes to produce placenta defect model mice. These model mice would be cured by gene edited in vivo by CRISPR/Cas system. We anticipate that this gene therapy would rescue the placenta defects in mice.