This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrine System, Subject name: Physiology
JAK/STAT signalling cascade is employed by: 
Select and explain. 
A. Growth hormone, B. Thyroid hormone, C. Insulin, D. Glucocoicoids
A: Growth hormone
Answer: A: Growth hormone 
Explanation: Growth hormone receptor is a transmembrane receptor which is associated with JAK-STAT pathway signalling. Other hormone which has JAK-STAT signalling is prolactin Hormone which also acts transmembrane receptor which has intrinsic tyrosine kinase activity- Insulin, growth factors.