This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Lacis cells are found in: 
Select and explain. 
A. Brain, B. Liver, C. Kidney, D. None of the above
C: Kidney
Answer: C: Kidney 
Explanation: The renin in kidney extracts and the bloodstream is produced by the juxtaglomerular cells (JG cells). These epitheloid cells are located in the media of the afferent aerioles as they enter the glomeruli. The membrane-lined secretory granules in them have been shown to contain renin. Renin is also found in agranularlacis cells that are located in the junction between the afferent and efferent aerioles, but its significance in this location is unknown. Ref: Ganong's Review of Medical Physiology 23rd edition, Chapter 39.