Uhhh... all "fiction" could be described as "lies," as fiction tells a story that is not true.
And furthermore, Dan Brown himself has claimed that his book is based on "fact" even though the characters are fictional.
Now, THAT is an oft-repeated lie. Brown claimed that the art and architecture are as described and the 'secret' rituals are or were done as described, but that the story is pure fiction.
Even that isn't true, as an article in the NY Times of all places revealed.
And what about the film promotions saying, 'everything your father taught you about Christianity is wrong'? Brown has not done enough to clarify where his facts stop and where his fiction begins. Brown has resurrected the lies of Holy Blood, Holy Grail. That book has been totally debunked, but Brown is relying on those forged documents and debunked conspiracy theory and presenting them seemingly as factual.