In a landmark study published in Nature Cell Biology, Australian researchers,have revealed how COVID-19 can infect the human placenta. The research team grew placental tissue in the lab, using a state-of-the-art method developed by Professor Jose Polo and colleagues where human skin cells are "reprogrammed" into trophoblast stem cells (the cells that help a developing embryo attach to the wall of the uterus, forming part of the placenta). They found that ACE2, a protein that acts as the doorway for SARS-CoV-2 to enter organs such as the lung, is present in specific placental cells, like syncytiotrophoblasts (ST cells).