As a rate-limiting enzyme of the hexosamine biosynthesis pathway (HBP) involved in HA production, glutamine-fructose-6-phosphate aminotransferase (GFAT) plays a significant role in the CD44high/CD24low stemness of cancer cells [17], supports mesenchymal breast cancer cells through histone modifications [18], and contributes to epithelial-mesenchymal transition in in vitro studies [19,20]. The gene discussed is GFPT2; the disease is breast cancer.