You will be given a definition of a task first, then some input of the task.
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.

 Tissue - type plasminogen activator ( tPA ) regulates activation of plasminogen into plasmin and is expressed in various regions of the brain especially in the hippocampus [ 143 ] .
Output:
brain