MMP2 and amyotrophic lateral sclerosis: Using ELISA, the levels of MMP-2 and MMP-9 were measured within the serum of thirty ALS (Group 1, Table 1: 18 males, 12 females; mean age ± SD, 59.4 ± 6.1 years) and twenty healthy, age-matched healthy controls (Group 2, Table 1, HC: 12 males, 8 females; 56.5 ± 2.3 years).