Board Thread:Naruto Discussions/@comment-24837927-20140421121126/@comment-3361615-20140427174304

Kekkei Genkai is associated with DNA.

All those with implants of Hashirama's cells, for example, have the KG Wood Release because these cells contains his DNA. Naruto only has access to the Son Goku's molded chakra, not his DNA. So Lava Release is Son Goku's KG, but not Naruto's.