Why does targeting tyrosine kinase receptors lead to either cell proliferation or cell damage/death?

Question

Quizplus · Accepted Answer

The Answer is The tyrosine kinase pathway leads to cell proliferation as shown by the effect of the appetite suppression peptide obestatin on a gastric cancer cell line. However, pertussis toxin (whooping cough) has opposite effects as indicated by its partial ability to block the action of obestatin via inhibition of phosphoinositide 3-kinase.

Why Does Targeting Tyrosine Kinase Receptors Lead to Either Cell