On the one hand, this effect in the long term may be unfavorable as GFAP-negative cells have been shown to have a higher average number of nucleolar organizer regions (Ag-NOR), an increase in which has been linked in a couple of papers to a worse prognosis in several cancers, including gliomas [257,258,259,260]. The gene discussed is GFAP; the disease is central nervous system cancer.