be in (one's) DNA

be in (one's) DNA

To be a core aspect of one's character, motivation, or lineage; to be an intrinsic or fundamental part of one. He's always been that way, ever since he was a small boy. Helping others just seems to be in his DNA. This company has been drilling oil since my great-grandfather first struck crude oil back in 1902. It's in our DNA!
Farlex Dictionary of Idioms.
See also:
  • part of the furniture
  • where (one) is coming from
  • where one is coming from
  • where somebody is coming from
  • where someone is coming from
  • percent
  • a hundred and ten percent
  • mask
  • (one's) mask slips