I don't know where that quote came from, but my understanding is some modern humans share 1 to 4 percent of Neanderthal DNA---suggesting interbreeding.
Hi NC. It is more accurate to say that modern humans from some parts of the world have received 1 to 4 percent of their genetic data from Neanderthals. The DNA is very nearly the same. The genes are there, it is just that the variants (actual encoded data) are somewhat different.
I'd also like to address a previous part of the discussion. Some are saying we are descended from Neanderthals. Some are saying we aren't descended from Neanderthals, but that we are a parallel branch with a common ancestor. In a sense, both statements are true, although the second statement is truer. Neanderthals are a different branch than Sapiens, but genes flowed into the modern Sapiens population from Neanderthals through interbreeding.