Four years ago, a 17-year-old immigrant girl named Jesica Santillan died at the Duke University Medical Center, the result of a botched heart-and-lung transplant following a blood typing mix-up. Her story opened a window on potent myths and inflammatory perceptions surrounding illegal immigration, border crossing, scarce health care resources and the widely misunderstood way in which we allocate transplant organs in the United States.

It is worth revisiting the myths; more important, though, we should acknowledge the complex realities that ought to inform current debates about immigration and health care reform.

Myth No. 1 -- Jesica's case highlights how undocumented immigrants come here for free health care, and how they wind up taxing and burdening the rest of us.

Reality -- Studies show that immigrants come here for jobs. A recent study by the Texas comptroller argued that the taxes paid by undocumented immigrants more than cover the state services they use. And if we are going to debate border-crossing for health care, let's be clear on who's doing it: Americans, frustrated with our own medical system, who venture from northern border states into Canada for cheaper drugs, to Europe and India for surgery, and into Mexico for alternative medicines.

In the transplantation world, the phenomenon of pressing moral concern is that of wealthy Westerners traveling to developing countries to purchase kidneys or other organs in unregulated black and gray markets. These kinds of border-crossing highlight real crises that ought to command more public attention than the much-hyped immigrant health care threat.

Myth No. 2 -- Jesica's case, in which she received not just one but two sets of mismatched organs, shows how the transplant system can be manipulated, in this case by an undocumented immigrant family jumping the line ahead of others.

Reality -- The two factors that got Jesica into the transplant system were health insurance (through her mother's job), and the generous private patronage of a supporter named Mack Mahoney and caring citizens in Franklin County, where she lived. Most undocumented immigrants have neither.

Moreover, many critics have a naive understanding of the transplant wait list. It is not a first-come, first-serve grocery checkout line. Once Jesica was listed, a number of factors determined the "match," such as her size and the size of the organs available, the extent of her illness, the immunological specifics of the available organs and which of the 11 U.S. transplant regions she lived in. Contrary to what many believe, we do not have a national "sickest-first" policy, although one was proposed and heatedly rejected during the Clinton years.

Myth No. 3 -- After Jesica died, her family refused to donate her organs, even though she had received two sets of transplants, showing how foreigners and illegal immigrants take more than they give.

Reality -- Hispanics in the U.S. donate organs at rates equal to their population; we have little data on donation by non-citizens. In Jesica's case, her organs were probably not transplantable because her body had been suffused with immunosuppressive drugs to prevent her type O body from rejecting a type A heart. Although critics from Bill O'Reilly to Michele Malkin used the case to inflame anti-immigrant passions, such scapegoating belies how little we know about how non-citizens and undocumented immigrants give to the system.

To be sure, Jesica's misfortune carries many other lessons -- about malfeasance and error, about the nature of American generosity as well as its limits, and about malpractice (the case helped squash a Republican congressional drive to cap malpractice awards for pain and suffering). The case also points to the tremendous and growing gap in supply and demand for transplant organs.

U.S. demand for organs shot up fivefold from 16,026 in 1988 to 90,000 in 2006, according to a recent Institute of Medicine report. In 2003, Jesica was surely a victim of building frustrations around scarce supply and heavy demand in this unique winner-take-all arena.

Four years later, a tragic case that inflamed public discussion might now enlighten it. Rather than embracing the myths, we should remember what Jesica Santillan's life, cut short, tells us about the reality of immigration and the American health care system, and about how passions of the moment can blind us to the real problems we must reform.

(Keith Wailoo is Martin Luther King Jr. professor of history and health policy at Rutgers University. He is co-editor, with Julie Livingston and Peter Guarnaccia, of "A Death Retold: Jesica Santillan, The Bungled Transplant, and the Paradoxes of Medical Citizenship.")