MIB1 and central nervous system cancer: A clinically significant correlation of MIB-1 LI and tumor growth may also be confirmed by the observation of a significant coherence of MIB-1 LI and tumor volume at diagnosis within the analyzed cohort, as gliomas showing a volume of > 20 cm3 at time of detection bearing a higher mean fraction of MIB-1 positive tumor cells compared to tumors measuring ≤ 20 cm3 at time of diagnosis, possibly indicating faster preoperative tumor growth velocity of PLGG bearing a higher MIB-1 LI.