She was always PRONE to melancholy.
Game of Thrones Season 4, Episode 8
Perhaps even taller, smarter
and less PRONE to freckling.
The Big Bang Theory Season 1, Episode 15
...who's PRONE to canker sores
The Big Bang Theory Season 4, Episode 23
Humanity is disorganized,
PRONE to destruction.
Westworld Season 3, Episode 8
If I was PRONE to sarcasm...
The Big Bang Theory Season 6, Episode 19