MKI67 and meningioma: Figure 4 shows the correlation between PTBE volume and ALPS index ipsilateral to meningiomas. On stepwise multiple linear regression analysis, ALPS index ipsilateral to tumor (β = −0.632; P < 0.001) was the only factor associated with PTBE volume. No correlations were found between PTBE volume and age (P = 0.226), sex (P = 0.856), tumor volume (P = 0.141), tumor location (P = 0.759), tumor grade (P = 0.713), or Ki-67 (P = 0.393).