Queen's Indian with ...Na6
With the black pieces, a typical Queen's Indian setup calls for the moves ...Nf6, ...e6, ...Be7, ...b6, ...Bb7, and ...d5. Literally dozens of move orders are possible and the setup can be used in response to several different schemes that White may offer. For now, I prefer to consider the cases where Black chooses a Queen's Indian setup vs a White fianchetto on g2.
In these types of games, there is always the question of what to do with the N on b8. Does it go to d7, where it might get in the way? Sometimes that's okay. Often, however, it makes sense to develop this Knight on a6. This game from the 2006 Olympiad between two strong GMs demonstrates these ideas.