Perhaps you should try some spelling variations:
decrease treg » decrease their (Expand search)
treg affected » trees affected (Expand search), are affected (Expand search), area affected (Expand search)
decrease the » decreases the (Expand search), decrease in (Expand search), decrease of (Expand search)
the decrease » to decrease (Expand search), and decrease (Expand search)
decrease can » decrease in (Expand search), decrease and (Expand search), decrease at (Expand search)
can decrease » and decrease (Expand search), can increase (Expand search), to decrease (Expand search)
decrease akt » decrease at (Expand search), decrease and (Expand search), decrease after (Expand search)
akt decrease » and decrease (Expand search), not decrease (Expand search), any decrease (Expand search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease the decrease can decrease ) OR ( decrease akt decrease treg affected ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease the decrease can decrease ) OR ( decrease akt decrease treg affected ))*.