SPH, or Surfactant associated 3, is a human gene encoded by SFTA3. It may also be known as: Surfactant-associated protein 3; SP-H; Surfactant-associated protein H; NANCI; SFTPH. The encoded protein has an amino acid length of 94 and a mass of 10.5 kDa. Homologs of this gene exist in other organisms, including: Fly.