A new system called MultiFate that was devised by researchers at Caltech, led by Allen Discovery Center for Cell Lineage Tracing principal investigator Michael Elowitz, Ph.D., recapitulates some of that cell-fate complexity through synthetic biology. The scientists engineered cells in the lab to carry a synthetic circuit that switches through combinations of three different proteins that regulate how genes are switched on or off, resulting in seven different “states.” In this movie made by Caltech doctoral student Ronghui Zhu, each cellular state is represented by a different color — as cells divide, the state is stably passed on to future generations.