Importantly, knockdown of Gfpt1, the rate-limiting enzyme for HBP in PDAC cells, reduced total O-linked N-acetylglucosamine (O-GlcNAc) levels and tumor growth both in vitro and in vivo [35], supporting the essential role of HBP and protein glycosylation in PDAC tumor maintenance and growth. The gene discussed is GFPT1; the disease is neoplasm.