This updated collection addresses the intense efforts that have been underway to characterize the cellular-molecular-biochemical elements of not only the hematopoietic stem cell niche but the niches for other stem cells. These specialized microenvironments that regulate stem cell function have continued to inspire tremendous interest as a subject of study in the years since the publication of the first edition. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls.