Which of the Following is an Inhibitory Extracellular Signal for Cell

Question

Which of the following is an inhibitory extracellular signal for cell proliferation?
A) EGF
B) TGFβ
C) Erythropoietin
D) IGF
E) PDGF

Accepted Answer

Transforming growth factor-β (TGFβ) and its relatives are amongst the best-understood inhibitory signal proteins.