T-Pit signal, which differentiates the most dorsal cells into corticotroph (C) (in orange) and Pit-1 induced in the caudomedial region of the pituitary gland, is the most complex, with five monomorph cell types: somatotroph (S) (in yellow), lactotroph (L) (in green), thyrotroph cells (T) (in violet), mammosomatotrophs (in yellow mixed texture) and plurihormonal linage tumor (in violet mixed texture). This evidence concerns the gene IRF6 and neoplasm.