In this task, you will be given sentences in which your task is to recognize the name of the organ of the body. An organ is a collection of tissues that structurally form a functional unit specialized to perform a particular function. Although there might be several correct answers, you need to write one of them.

Let me give you an example: I have serious allergy in my left eye.
The answer to this example can be: eye
Here is why: Eye is an organ which has been affected, hence should be tagged.

OK. solve this:
 Mean CBF values were higher in patients ( P < . 005 ) than in control subjects in all cerebral artery territories .
Answer:
cerebral