Researchers have developed a new organoid model to study the thymus, a crucial organ for training T cells of the immune system. These organoids, derived from mouse thymus tissue, specifically mimic thymic epithelial cells (TECs), which play a vital role in T cell training. This model allows long-term culture of TECs, providing new opportunities to understand their function. Insights gained from studying these organoids could potentially lead to new treatments for individuals with impaired thymus function. This study was published in Cell Reports on March 27, 2024.