This family consists of several mammalian neuroendocrine-specific golgi protein P55 (NESP55) sequences. NESP55 is a novel member of the chromogranin family and is a soluble, acidic, heat-stable secretory protein that is expressed exclusively in endocrine and nervous tissues, although less widely than chromogranins [1].

1: Neuroendocrine secretory protein 55: a novel marker for the constitutive secretory pathway. Fischer-Colbrie R, Eder S, Lovisetti-Scamihorn P, Becker A, Laslop A; Ann N Y Acad Sci 2002;971:317-322. PMID:12438142