While mitotic count is a primary criterion for grading ANNUBP versus low-grade MPNST (LG-MPNST requires 3–9 mitoses/10 HPF without necrosis), the elevated Ki-67 strongly indicates increased proliferation beyond a typical neurofibroma and aligns with findings in ANNUBP or even LG-MPNST. The gene discussed is MKI67; the disease is malignant peripheral nerve sheath tumor.