MKI67 and central nervous system cancer: The results revealed that i) LGR5 was positively expressed in all glioma specimens and its expression increased with pathologic grade and Ki-67 expression; ii) LGR5 was highly expressed in three glioma cell lines and its expression was reduced significantly by siRNA; and iii) RNAi-mediated downregulation of endogenous LGR5 in U87 cells resulted in the suppression of cell proliferation, arrest of the cell cycle, and reduction in clone and tumorsphere formation in vitro.