Core Viewpoint - The research presents a novel method for constructing embryonic models using chemically induced embryonic founder cells (EFC), which allows for a more efficient and accurate simulation of mouse embryogenesis and organogenesis [2][3][6]. Group 1: Research Methodology - The study utilized small molecules (CHIR-99021, E-616452, Lif, AM580) to induce mouse embryonic stem cells into 8-16 cell stage embryonic founder cells (EFC) [6]. - EFC cells can determine all lineages of blastocysts both in vivo and in vitro, enabling the construction of a complete embryonic model [6][9]. - The model accurately replicates the developmental process starting from organ formation, including the formation of three germ layers and early organ structures [6][9]. Group 2: Research Highlights - The system using EFCs allows for direct, rapid, efficient, and accurate construction of in vitro embryonic development models [8]. - Induced EFCs (iEFC) can generate a scalable and faithful embryonic model (iEFC-EM) that reproduces mouse embryonic development up to the organ formation stage [9]. - The model demonstrates the transformation of epithelial cells to mesenchymal cells during gastrulation, leading to the development of various early organ precursors and structures [6][9].