el ium ▁and ▁pro static ▁u ro th el ium ; ▁there ▁is ▁a ▁significant ▁inter - ind ividual ▁vari ability . ▁Two ▁morph olog ic ▁types ▁have ▁been ▁described : ▁the ▁open ▁type , ▁extending ▁sl ender ▁ap ical ▁processes ▁to ▁the ▁du ct al ▁or ▁ac inar ▁l umen , ▁and ▁the ▁closed ▁type ▁cells , ▁which ▁lack ▁l umen al ▁pro tr us ions ▁but ▁display ▁d end rite - like ▁processes ▁that ▁extend ▁between ▁adjacent ▁ep ith el ial ▁cells . ▁ ▁Ne uro end ocr ine ▁cells ▁in ▁the ▁human ▁pro state ▁contain ▁a ▁diverse ▁array ▁of ▁secret ory ▁products : ▁ser ot on in ▁( which ▁is ▁present ▁in ▁virt ually ▁all ▁ne uro end ocr ine ▁pro static ▁cells , ▁chrom og ran in ▁A ▁( C g A ), ▁syn apt oph ys in ▁and ▁neur on - specific ▁en ol ase ▁( N SE ) ▁( three ▁prote ins ▁that ▁are ▁used ▁as ▁markers ▁for ▁ne uro end ocr ine ▁cells ) ▁cal cit on in ▁and ▁other ▁pe pt ides ▁of ▁the ▁cal cit on in ▁family ▁( cal cit on in ▁gene - related ▁pe pt ide ▁( CG R P ) ▁and ▁k ata cal cin , ▁which ▁col ocal ize ▁to ▁the ▁cal cit on in - cont aining ▁cells ), ▁bomb es in / g astr in - re le asing ▁pe pt ide ▁( GR P ), ▁thy roid ▁stim ulating ▁h orm one - like ▁pe pt