The quantification of these three IHC patterns as percentage of tumor, as well as of the density of NHERF1 dot/microlumen-like structures, showed significant correlation between the extent of dot/microlumen-like pattern and the microlumen density (r = 0.73, p = 0.000002; Figure 3E), and resulted in the classification of chordoid meningiomas in three categories (Figure 3D–3E). This evidence concerns the gene NHERF1 and Chordoid Meningioma.