MMP3 and Alzheimer disease: Previous research has shown that HL in patients with rheumatoid arthritis is linked to damage to inner ear hair cells by MMP3 through oxidation.10At the same time, Zhang et al11found that the expression level of MMP3 in Alzheimer's patients with HL was significantly elevated by exploring the clinical features and potential mechanisms related to pathological neuromarkers and blood-brain barrier in Alzheimer's disease and HL, which also confirmed that the expression of MMP3 gene is closely related to HL.