Authored by Steven Quay and Richard Muller, the article discusses the genetic fingerprint of the “double CGG” combination that appears in the virus:

Although the double CGG is suppressed naturally, the opposite is true in laboratory work. The insertion sequence of choice is the double CGG. That’s because it is readily available and convenient, and scientists have a great deal of experience inserting it. An additional advantage of the double CGG sequence compared with the other 35 possible choices: It creates a useful beacon that permits the scientists to track the insertion in the laboratory. Now the damning fact. It was this exact sequence that appears in CoV-2.

　Despite this, the virologists involved in the gain-of-function research on coronavirus sought to hide the existence of this double CGG fingerprint:

　When the lab’s Shi Zhengli and colleagues published a paper in February 2020 with the virus’s partial genome, they omitted any mention of the special sequence that supercharges the virus or the rare double CGG section. Yet the fingerprint is easily identified in the data that accompanied the paper. Was it omitted in the hope that nobody would notice this evidence of the gain-of-function origin?

But in a matter of weeks virologists Bruno Coutard and colleagues published their discovery of the sequence in CoV-2 and its novel supercharged site. Double CGG is there; you only have to look. They comment in their paper that the protein that held it “may provide a gain-of-function” capability to the virus, “for efficient spreading” to humans.