Tissue-resident adult stem cells are the source of organ and tissue development, regeneration and maintenance. In many tissues they are also suspected as cancer cells-of-origin, both due to their long life-span as well as their self-renewal and regenerative capacities. As such, adult stem cells are a link that connects the closely related biology of development and tumorigenesis. It is becoming increasingly clear that stemness is a cell state, rather than a final cell identity. Cells shift their state as part of normal development and of oncogenic progression and invasion. The regulatory mechanisms that control shifts in cell state also control development and cancer and appear to involve all levels of regulation: from genetic, epigenetic and epi-transcriptomic to post-transcription, post-translation and classic cell signaling pathways. I am interested in understanding the regulatory mechanisms that control adult stem cells in the contexts of development and cancer, particularly in the earliest stages of tumorigenesis, when the developmental program deviates towards cell transformation.