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.
One example: I have serious allergy in my left eye.
Solution is here: eye
Explanation: Eye is an organ which has been affected, hence should be tagged.

Now, solve this:  The extracorporeal membrane used in a continuous renal replacement therapy ( CRRT ) for the treatment of a critically ill patient with acute renal failure ( ARF ) is vitally important for several reasons , including its influence on biocompatibility and filter performance .
Solution:
renal