MAPT and cutaneous mastocytosis: In conclusion, we found that plasma sST2 levels are elevated in children with CM and in children with SMA, with the greatest elevation seen in children with CM; that CSF sST2 levels are also elevated in children with CM, likely due to leakage of plasma sST2 across an impaired blood-brain barrier; that elevated plasma sST2 is associated with an increase in parasite biomass, endothelial activation, and levels of the neuronal injury marker tau; and that in children with CM who are ≥5 years of age at the time of CM, elevated plasma sST2 is associated with long-term neurocognitive impairment.