Be concerned about race (4)
I believe the answer is:
care
'be concerned' is the definition.
(I've seen this before)
'about race' is the wordplay.
'about' indicates anagramming the letters.
'race' anagrammed gives 'CARE'.
(Other definitions for care that I've seen before include "Have concern or regard" , "Worry" , "Have affection (for)" , "Safekeeping" , "The provision of what's necessary, for health say" .)