HAS2 and cancer: Deregulated HAS2-synthesized hyaluronan is tightly connected to the malignant phenotype of solid tumors, such as breast cancer,26, 27 and the interaction between hyaluronan and its hyaluronan-binding proteins promotes cancer stemness;8 therefore, further elucidation of the mechanisms that regulate the ubiquitinylation of HAS2, and thus its stability and activity, is highly desired.