Part 1. Definition
In this task, you are given a sentence. You are expected to write the name of the organism substances in the body mentioned in the input. Although there might be several correct answers, you need to write one of them.
Part 2. Example
Antisperm antibodies were assessed in the serum samples of 73 men unable to ejaculate naturally and on the sperm cells of 13 of these men.
Answer: serum
Explanation: Serum is a substance of the organism and needs to be tagged.
Part 3. Exercise
 Plasma gelsolin can be considered an amateur chaperone , as it binds Abeta and not only inhibits its Abeta fibrillization but is also capable of degrading preformed Abeta fibrils [ 149 , 150 ] .
Answer:
Plasma