HIF1A and glioma: For instance, CD133 stability is regulated in hypoxia by GLT8D1 (Glycosyltransferase 8 Domain Containing 1), a transmembranal glycosyltransferase highly expressed under hypoxia by the HIF1α transcription factor [33] GLT8D1 co-localizes with CD133 in microvilli of glioma stem-like cells, where it glycosylated CD133, hindering its degradation via the endosomal-lysosomal pathway.