Brothers — Ben Bova

What if, instead of being transplanted, hearts, livers, and kidneys could simply be regrown like a lizard's tail? This turns out to be a faint possibility in Arthur Marshak's genetic lab. He encourages his research staff to pursue it, but political and corporate threats loom in addition to the scientific problems. Even his brother, Jessie, a renowned physician, turns against him, leaving Julia, the love of both their lives, caught in between. By weaving flashbacks from a scientific inquiry into the ethical and medical questions of rejection, Bova adds the tension of courtroom drama to a medical thriller.