Alongside the reduced ISC populations observed in IBD,15 the impaired capacity of IBD-derived organoids to grow in vitro51,52 further contributes to the notion that ISCs in IBD are dysfunctional.53 In the mouse gut, a recent study identified 3 distinct stem cell populations based on scRNA-seq, indicating that ISC biology may be more complex.54 Type I slow cycling stem cells are enriched in LGR5, possessing more stem-like features, whereas type II and III ISCs are more differentiated and proliferative, concurrently expressing major histocompatibility class II. The gene discussed is LGR5; the disease is inflammatory bowel disease.