In agreement with previous findings [3], CSF concentrations between 10 and 5% (v/v) allowed high cell viability, therefore, CFS were tested at 10% (v/v) for their capacity to modulate the mRNA and protein levels of TNF-α, IL-8, IL-12 and IL-10, i.e. cytokines involved in the inflammatory process and with immune-regulatory function [54, 55]. Here, CXCL8 is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.