Soon after the Twin Towers fell on Sept. 11, 2001, another set of frightening attacks hit our nation. Spores of the deadly disease known as anthrax were mailed to news media and Congressional offices, killing five people and sickening 17 more. All these events left Americans feeling quite vulnerable to terrorism, including bioterrorism.

Today, anthrax has faded from the headlines. But scientists and defense experts still work to avoid a comeback. An article published recently in the Proceedings of the National Academy of Sciences includes surprising information about how different people respond to anthrax.

Anthrax is a bacterium that produces “anthrax toxin” inside its victims. The toxin is what makes people really sick. But the new research shows it may not be super dangerous for everyone. Some people seem to handle it better than most.

The scientists say expression of a particular gene is partly responsible. The main purpose of that gene, known as CMG2, is to promote capillary growth and aid formation of umbilical veins.

But researchers say the gene also affects how the main component of anthrax toxin binds to cells. It produces a protein in cell membranes that the toxin uses as a latching-on point. The less toxin bound to a cell, the better chance it has of surviving. Other factors also affect anthrax susceptibility, but CMG2 is a major influence.

Of 234 people studied, three were extremely resistant to anthrax toxin. But vulnerability in the remaining group of subjects still varied greatly. Some people were 250 times more susceptible to anthrax toxin than others.

Scientists may one day use information on anthrax susceptibility to predict who would likely survive an anthrax attack, and who would be good first responders. Let’s hope the people with the best genes want the job.