Level of VEGF-A in serum (A) and CSF (B) of ALS patients with respiratory dysfunction. Boxes include values from first quartile (25th percentile) to third quartile (75th percentile). Lower and upper error bar refers to 10th and 90th percentile respectively. The thick horizontal line in the box represents median for each dataset. Levels of VEGF-A were normalized to total serum and CSF protein respectively. Outliers are shown in circles. # indicates significant difference (p < 0.05) between the given conditions. Data was analyzed by Mann Whitney U Test. ALS, Amyotrophic Lateral Sclerosis; VEGF-A, vascular endothelial growth factor-A; pg, picogram; μg, microgram.