You will be given a definition of a task first, then some input of the task.
In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

Psychoneuroimmunology ( PNI ) is the study of the interaction between psychological processes and the nervous and immune systems of the human body .
Output:
Psychoneuroimmunology ( PNI ) , also referred to as psychoendoneuroimmunology ( PENI ) or psychoneuroendocrinoimmunology ( PNEI ) , is the study of the interaction between psychological processes and the nervous and immune systems of the human body .