It is the Prequel to DaVinci Code.
The DVC does not really follow on from it except in the first chapter where he speaks of his love, Vittoria, what happened 'last month' and the reason behind why they would be calling him. The religious cryptology, because he dealt with religious issues in Angels and Demons. There is no significance, but I am dislking how the preview for A&D seem to be promoting it as a sequel.

I thought it was fantastic.
It is very much dealing with the idea that Genesis and The Big Bang can co-exist, etc. It is a bit strange in parts, but oh-so-thrilling. It is very, very captivating and if you are an anxiety freak over scary books and movies like me, read it mostly in the daytime!