In contrast, after the first demonstration of S100B in the extracellular compartment in the late seventies of the last century, when elevated levels of the protein were detected in the cerebrospinal fluid of multiple sclerosis patients in the acute phase, whereas lower levels were found in the stationary phase of the disease [16], growing evidence indicates an increasingly clearer role for S100B when secreted in the extracellular compartment. The gene discussed is S100B; the disease is multiple sclerosis.