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
[{'content': 'JAK/STAT signalling cascade is employed by: \nSelect and explain. \nA. Growth hormone, B. Thyroid hormone, C. Insulin, D. Glucocoicoids', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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.', 'role': 'assistant'}]