At the genetic level, the analysis of polymorphisms in the MMP-3 (-1171 5A/6A) and MMP-9 (C-156T) genes indicated that the -1171 6A MMP-3 allele (which was associated with reduced promoter activity) was associated with AD whereas the MMP-9 polymorphism was not [142]. The gene discussed is MMP9; the disease is Alzheimer disease.