'Here, we discuss three preprints that take advantage of the experimental strengths of #hPSC-derived tissues to investigate new mechanisms in development and disease. In one preprint (Wong et al., 2022 preprint), the authors have developed an hPSC model to investigate the mechanisms by which a rare and transient population of cells, the ventral foregut endoderm, becomes committed to specific endoderm lineages. We also discuss two preprints (Victor et al., 2022 preprint; Zhao et al., 2022 preprint) describing how hPSCs are being used to identify which cell types in the brain are driving the pathology of a genetically caused form of #Alzheimer's disease.'