Therefore, abnormal amount of MMP-9 in ALS could be a result of uncontrolled MMP-9 release due to non-specific atrophy of muscles and nerves in the course of the disease or other non-genetic mechanisms, such as modification of transcription by various cytokines, activation of latent MMPs as well as inhibition of MMP-9 by their tissue inhibitors (Montaner et al. 2003; Zawiślak et al. 2009). The gene discussed is MMP9; the disease is amyotrophic lateral sclerosis.