There was a significant positive correlation (p<0.0001, Pearson product-moment correlation) between corrected CSF angiogenin levels and corrected plasma angiogenin levels in controls, whereas in ALS patients (p = 0.21) the observed correlation was attenuated (figure 3; r2control  = 0.13, r2ALS  = 0.011). This evidence concerns the gene ANG and amyotrophic lateral sclerosis.