In this seminar, I explore the pivotal role of tissue stem cells and their microenvironment, known as the niche, in regeneration. With a focus on the endothelial cell niche, my work introduces an innovative in vitro vascularized perfusable model tailored for human tissue explants and organoids. My findings also highlight the crucial contribution of paracrine factors derived from lymphatic endothelial cells in facilitating intestinal regeneration and repair in vivo. I will also outline future research directions for my independent laboratory, where I aim to unravel the complexities of endothelial cell interactions and paracrine signaling in tissue regeneration. The overarching goal is to leverage this knowledge for engineering vascularized and physiologically relevant organoids, advancing our understanding of regenerative medicine and stem cell biology.