Figure 2From: Measurement of cystatin C functional activity in the cerebrospinal fluid of amyotrophic lateral sclerosis and control subjectsCorrelation of cystatin C concentration with papain inhibition assay activity and cystatin C activity. (A) Total assay activity was indirectly related to cystatin C concentration, and the relationship was statistically significant (p < 0.001, Spearman r = -0.861). (B) Total cystatin C activity was directly related to its own concentration, and the correlation was strong and significant (p < 0.001, Spearman r = 0.883).Back to article page