Excessive immunoglobulin G (IgG) and S100A4 proteins were identified in the intracranial vascular walls of patients with MMD, indicating that the deposition of IgG causes damage to the internal elastic lamina and causes S100A4 + SMC migration, which causes lumen stenosis and compensatory vessel formation [34]. This evidence concerns the gene S100A4 and multiminicore myopathy.