MCM2 and meningioma: All four meningiomas lacking MCM2 and ACADL immunostaining (IHC-G1) were classified as integrated grade 1; all three meningiomas in IHC-G2 (ACADL + /MCM2-) were classified as integrated grade 3, whereas 5/8 tumors in IHC-G3 (MCM2 +) were classified as integrated grade 2 or 3 (P = 0.0166).