Table 1. Categorization of proteins in the rostro-caudal gradient study.

Fold change	R-square	Definition	# Proteins
≥ 1.5	> 0.7	Affected	60
< 1.5	> 0.7	Uncertain	41
> 1.2	0.3-0.7	Uncertain	79
< 1.2	0.3-0.7	Unaffected	44
	< 0.3	Unaffected	55

Fold change and R-squared limits for defining proteins quantified in the rostro-caudal gradient (RCG) iTRAQ experiment as affected, uncertain or unaffected by the gradient. The fold change and R-squared limit is calculated between the 1-2^nd and 44-45^th mL of CSF, referred to as RCG point 1 and 7.