While there appeared to be a statistically significant decrease in the mean level of active MMP-9 in ALS (0.23 ± 0.74 ng/ml) as compared to OND (1.15 ± 0.40 ng/ml) (p < 0.0001; Cohen’s d = −1.41), their levels were at the lower level of detection of the assay and deemed too low for the statistical analysis to have any degree of confidence (Figure 13). This evidence concerns the gene MMP9 and amyotrophic lateral sclerosis.