PFKFB4 is one of the four genes that encode 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase, and its mRNA levels significantly differentiate IDH1 wild-type primary glioblastomas from the secondary glioblastomas and from IDH mutant gliomas. The gene discussed is PFKFB4; the disease is glioblastoma.