Linheng Li is a senior investigator at the Stowers Institute for Medical Research and a leader in stem cell biology. Using hematopoietic and intestinal stem cells as model systems, his research has identified stem cell niches in bone marrow and further defined how niche-derived signaling pathways—including Wnt/β-catenin, PI3K/Akt, and BMP signaling—govern stem cell identity and fate, and how their dysregulation contributes to aging, impaired regeneration, and cancer. His work helped shift the field from a stem cell–intrinsic view to a niche-centric framework, revealing shared signaling logic that bridges developmental biology, adult stem cells, and cancer. These discoveries have important translational implications for hematopoietic stem cell expansion and regenerative medicine. More recently, his research has focused on cancer stem cells and their microenvironment, uncovering mechanisms of immune evasion and immunosuppressive niches with implications for overcoming cancer stem cell immune escape and tumor immunosuppressive barrier.