The y Factor (Cresperian)

When a stranger invades geneticist Mai Trung's office, he has to say only one word to get her interested in leaving with him: Xenobiology. Rumors have been rife about aliens on Earth, but only a select few know that they arrived on widely scattered lifeboats from a wrecked spaceship. Mai is brought into the secret group working with a few of the surviving aliens because they have one trait that is almost incredible for its implications: They can turn themselves into perfect humans. More than perfect, actually. Closer to superhuman. And Mai is told she will be working with one of the aliens in order to help figure out how to apply that ability to humans; to heal injuries, to slow or even reverse the aging process, to make oneself healthier or more attractive. In the meantime, other scientists are re-engineering some of the alien technology in order to build a faster-than-light spaceship before other nations who have captured aliens do so. From that first word in her office, Mai begins an incredible journey that will eventually take her to the stars and into a whole new existence. Sequel to Human by Choice.