[roadnottaken]

No, the KRAS mutations are somatic (spontaneous), not inherited

[AustinDev]

So presumably something causes the spontaneous mutations?

[M95D]

Nature.

DNA is unstable. Lots of stuff cause mutations: background radiation, chemicals, viruses, even our own normal metabolism [1].

[1] https://en.wikipedia.org/wiki/Reactive_oxygen_species#Oxidat...