It showed pocket-like small extracellular spaces with irregular microvillus-like projections in a poorly differentiated chordoid meningioma from the 2nd group, and well-formed microlumens in well-differentiated tumors from the 3rd group, in good correlation with the histology and NHERF1 immunostaining. The gene discussed is NHERF1; the disease is Chordoid Meningioma.