Shop I ran set up (4)
I believe the answer is:
deli
'shop' is the definition.
(delicatessen)
'i ran set up' is the wordplay.
'ran' becomes 'led' ('lead' can be a synonym of 'run').
'set up' says the letters should be written backwards (in a down clue, letters go up).
'i'+'led'='iled'
'iled' backwards is 'DELI'.
(Other definitions for deli that I've seen before include "Specialist food shop" , "Special shop" , "Specialised food shop" , "Cold-meat counter" , "Specialist foodshop(abbr.)" .)