Perhaps you should try some spelling variations:
antigen processing » antigen presenting (Expand search), ration processing (Expand search)
decrease antigen » release antigen (Expand search), decrease nitrogen (Expand search), decreases mitogen (Expand search)
decrease during » increase during (Expand search), increases during (Expand search), increased during (Expand search)
during decrease » during increased (Expand search), during depressed (Expand search), during disease (Expand search)
decrease to » decreased to (Expand search), decrease toc (Expand search), decrease the (Expand search)
decrease on » decrease in (Expand search), decrease of (Expand search), decrease or (Expand search)
on decrease » on decreased (Expand search), or decrease (Expand search), of decrease (Expand search)

You may be able to get more results by adjusting your search query.

• Removing quotes may allow a broader search: (( decrease during decrease antigen processing ) OR ( decrease to decrease on decrease ))~.