What is it good for, exactly? I just got it instead of Faint Heart for my Puma, Panja, because I didn't like the Faint heart(It decreased his Courage by 50%!). But what exactly does this gene do? It has 0% frequency, so..

We have diseases in the game concept but they aren't introduced yet. Immunity genes shouldn't be found among the pets now but Mutagen mechanism pulled it out. This issue won't repeat anymore, we fixed it.

We removed this gene from your Puma and changed it to Lionheart. Though this pet can't benefit from this gene (Normal organs have more genetic power than any other Internal Organs gene) but his offsprings can :)

Thanks for pointing us this issue!

Oh! I didn't know it was a bug, thank you for fixing it Angel!