Through comparative clinical studies measuring serum endoglin in postherpetic neuralgia (PHN) patients versus healthy controls, and animal investigations using spared nerve injury (SNI) rat models with recombinant endoglin intervention, we assessed mechanical/thermal hyperalgesia, microglial activation, inflammatory cytokines, BSCB permeability, and TGF-βRI/Smad2/NR2B phosphorylation. The gene discussed is SMAD2; the disease is postherpetic neuralgia.