FM19G11 is an inhibitor of Hypoxia Inducible Factors α (HIFα), reported to affect self-renewal and differentiation of stem cells. Hypoxia-inducible factors (HIFs) are transcription factors that respond to changes in available oxygen in the cellular environment. Among other functions (like angiogenesis), HIFα proteins affect the self-renewal and the differentiation processes of stem cells. FM19G11 inhibits the HIFα proteins that repress the target genes of the two α subunits, in various tumor cell lines as well as in adult and embryonic stem cell (ESC) models.