in the/somebody's blood/genes

in the blood

Innate, as of a skill or quality. That type of passion can't be taught—it's in the blood.
See also: blood
Farlex Dictionary of Idioms.

in the blood

 and in one's blood
Fig. built into one's personality or character. John's a great runner. It's in his blood. The whole family is very athletic. It's in the blood.
See also: blood
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

in the/somebody’s ˈblood/ˈgenes

part of somebody’s nature and shared by other members of their family: Both his father and his mother were writers, so literature runs in his blood.
See also: blood
Farlex Partner Idioms Dictionary
See also:
  • in the blood
  • be in (one's) blood
  • after (one's) blood
  • after your blood
  • be after (one's) blood
  • be after/out for somebody's blood
  • in (one's) blood
  • in blood
  • in one’s blood
  • in your blood