The average numbers of NeuroD1 expressing cells in normal adenohypophysis specimens were significantly lower than in the adenomas overall (<i>p</i>=0.006).
The functional differentiation of pituitary cells and adenomas follows the combination of transcription factors and co-factors in three cell lineages [growth hormone-prolactin-thyroid-stimulating hormone lineage, adrenocorticotrophic hormone (ACTH)/pro-opiomelanocortin (POMC) lineage, and follicular stimulating hormone (FSH)/luteinizing hormone (LH) lineage], which include Pit-1, GATA-2, SF-1, NeuroD1/beta2, Tpit, ERalpha, and others.
NeuroD1 mRNA was widely expressed in PA (82%), with measurable levels found especially in those derived from Pit-1 independent lineages, i.e. corticotroph (5/5) and clinically non-secreting (CNS) adenomas (9/11).