For example, Phi et al. [4], in their multivariate analysis of 33 children with infratentorial ependymoma, showed that the shorter PFS correlated with anaplastic histology of the tumour (P = 0.004), a higher mitotic counts (P = 0.001) and a higher Ki-67 index (P = 0.004). This evidence concerns the gene MKI67 and ependymoma.