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:
 Inhibition of platelet aggregation was also observed with the N - terminal fragment of lactotransferrin ( residues 3 - 281 ; 50 % inhibition = 2 microM ) and with CFQWQRNMRKVRGPPVSC synthetic octodecapeptide ( residues 20 - 37 ; 50 % inhibition = 20 microM ) corresponding to one of the two external loops ( residues 28 - 34 and 39 - 42 ) where we recently located the receptor - binding site .
Answer:
fragment