Epithelial tissues are composed of polarized, adherent cell sheets that contain proliferative, long-lived stem cell populations. Each of these features is essential for the proper function of these diverse tissues. Cell polarity ensures directional fluid secretion in glandular epithelia such as the mammary gland and lung. Adhesive properties promote epithelial barrier function, which is crucial for pathogen exclusion, as exemplified by the epidermis and intestine. Stem and progenitor cells are critical for establishing, maintaining, and restoring epithelial structural and functional integrity. Nevertheless, defective epithelial polarity, adhesion, and stem cell function have each been linked to tumorigenesis; therefore, it is no surprise that most human cancers are epithelial-derived. Taken together, this knowledge underscores the importance of developing improved methods to dissect epithelial stem cell behaviors throughout development, homeostasis, and disease. This special collection will focus on new technological advancements in epithelial biology that may yield important insights into regulators of stem cell dynamics in both normal and disease contexts. The goal is to showcase innovative new technologies developed in diverse epithelial tissues from a variety of model systems. Another priority of this collection is to incorporate a combination of in vivo, ex vivo, and in vitro experimental approaches to provide a broad perspective on the latest technologies.