The gene is constantly active and produces low amounts of a protein that is found everywhere in his body as well as on his skin.
He is close to the people he works with, having referred to them as a surrogate family in a message to his sister Jeannie.As to Jeannie, Mc Kay thinks that she is wasting her talents with “just living a family life.” Having no contact with his sister for several years, Mc Kay has since restored their relationship and is enjoying the company of his niece.Although Mc Kay enjoys deriding medicine as voodoo and fake science, he considered Dr.Carson Beckett to be “the closest thing to a best friend” he ever had.He is a rather good team-player and follows orders, even if he will nag about things contrary to his own opinions.
Despite his irritating demeanor, many members of the Atlantis expedition are on friendly terms with him.
That included taking the initiative to hand-carry, and then throw, a Naqadah generator through the Stargate in order to lure a creature of floating energy out of the city.
And evacuating entire populations from planets about to be destroyed.
His drawback is his off-putting personality and style. Still, using those lightning-quick mental reflexes to save the day does wonders.
Some humans have a rare DNA tag marking them as a descendant of the Ancients.
This allows Mc Kay to activate and use Ancient equipment, weaponry and ships, such as those provided by the Atlantis base.