in certain cultures of midgut carcinoid tumour cells , two different phenotypes developed : small rounded endocrine tumour cells with positive immunoreactions against 5-ht and tachykinins ( tk ) , and large elongated neuron-like cells , which gradually lost 5-ht immunoreactivity , while tk immunoreactivity remained unchanged .
C1334763
midgut carcinoid
C0014136
endocrine