The expression level of 5-LOX/ALOX5 in GBM tumors does not affect prognosis [9,188], although simultaneous high expression of COX-2 and 5-LOX/ALOX5, two major ARA C20:4n-6 processing enzymes, is associated with a worse prognosis [188]. The gene discussed is PTGER2; the disease is glioblastoma.