Locking the Fate: How PROX1 Represses Plasticity and Liver Cancer

A Transcriptional Ridge in the Waddington Landscape. The Waddington landscape model, proposed in 1957, provides a powerful framework for understanding cell fate determination (Waddington, 1957). As development progresses, cells become restricted to distinct fates, separated by high "ridges" that prevent identity switching. A recent study in Nature Genetics uncovers such a ridge in hepatocyte lineage specification (Lim et al., 2025). Lim et al. report that prospero homeobox protein 1 (PROX1) acts as a hepatocyte-specific safeguard repressor, ensuring lineage stability by actively suppressing alternative cell fates and preventing cholangiocarcinoma development.