some organ-specific cell types express the enzyme constitutively ( mesangial cells , renomedullary interstitial cells , thymic subcapsular epithelium , colonic pericryptal fibroblasts ) , while in others it seems to be induced either by external stimuli ( epithelium of the female breast ) or as part of their differentiation/maturation program ( developing nephrons , enterocytes of the small intestine ) .
C0014609
epithelium
C0682610
enterocytes