HERVs do make up nearly 8% of the entire human genome. Until recently, scientists believed these viral fossils were just junk. But there's now a great deal of speculation that HERVs may contribute to some conditions such as cancer, autoimmune diseases, and neurological disorders. Understanding HERVs may open up all sorts of therapy options in the future.

The Human Body does emit radiation, but nothing like the book describes (lot of fiction there).

Every object (including the human body) at a temperature greater than absolute zero emits thermal radiation.

Humans also emit radiation from isotopes inside the body, the most common being potassium-40--an isotope that occurs as a significant fraction of all potassium (which humans require to live). In fact, a banana equivalent dose (BED) is a standard measure of radiation exposure that equals the radiation a person will absorb when eating one banana.

All factual.

I had never heard of the Berlin Patient or the procedure that made him effectively HIV-negative before researching the book. The method of treatment (bone marrow transplant from a donor who carried CCR5-delta32) is too cost-prohibitive to be administered on a wide scale, but the breakthrough has opened up new research possibilities--and new hope that a cure could be around the corner.

See this link for more.

Factual. Although...

The most interesting thing I learned in researching both pandemics was that each was preceded by a massive volcano--in both instances from present-day Indonesia.

It also appears that both pandemics (The Plague of Justinian in the sixth century and The Black Death in the fourteenth century) were caused by the same pathogen: Yersinia pestis (Y. pestis).

So the two most deadly plagues in recorded history were both caused by the same pathogen and BOTH were directly preceded by a massive volcanic eruption in present-day Indonesia.

Both plagues were incredibly important--historically. The Plague of Justinian in many ways led to the fall of the ancient world and the dawn of the dark ages. The population decline and the weakening of the world's greatest empires (including The Eastern Roman Empire and Persia) ended a more or less constant march of progress across tens of thousands of years since the Toba Catastrophe.

Here are some details on both pandemics:

The Plague of Justinian in the sixth century was the first "super pandemic" in recorded human history. There's very strong evidence that this pandemic was the direct result of the Indonesian volcano Krakatoa. But the jury is still out... See this link for more.

The Black Death in the fourteenth century, gets a lot more press, mostly because there are more details about it in the historical records. We know that it was incredibly similar to The Plague of Justinian (same pathogen, same point of origin, supposedly: China).

A recent discovery really tied the entire volcano-plague thesis together and gave me a great opening with the plot. Researchers now believe a volcano in Indonesia around 1257 led to widespread famine and a volcanic winter across Europe: http://www.insidescience.org/content/source-13th-century-volcanic-calamity-discovered/1426

The Black Death occurred almost a hundred years later, but... that was close enough for me!

The volcano at Krakatoa around 535 was very much like a Second Toba Catastrophe: we see a massive reduction in human population (mostly due to the plague that followed) and a thousand years later, a huge leap forward in human progress (The Renaissance).

It sort of made sense with the larger arc of the series and I found the volcano-plague connection very interesting.

All the details about the Proto-Indo Europeans (PIE) in the novel are factual (to my knowledge).

To me, they're one of the most fascinating and little-discussed groups in history. Hopefully we'll learn more in the coming years.

The details regarding the Knights' defense of Malta over the years is all factual.

Them hiding out in St. Paul's Catacombs... Fiction!

Fiction. And let's hope it stays that way.