Transplant surgery puts patients at much higher risk for skin cancer by weakening the immune system. That’s why, for one young transplant patient, a simple gift of sunscreen proved to be (as the advertising slogan goes) “priceless.”

Squamous cell carcinoma HIV, several diseases, and certain medicines used in treating organ transplants and other conditions all have something in common: They can weaken the immune system, leading to skin cancers.

Here’s another reason to get close to someone you love. New research from Northwestern and Pennsylvania State Universities suggests that couples who do skin self-exams together have a better chance of catching skin cancers earlier, when they are less disfiguring and more readily curable. The study found that when people learn to work as a couple, they take the exams more seriously, performing them more carefully than individuals who learn to do the exams alone.

Since melanomas are most curable when caught early, it’s understandable that physicians might be aggressive in removing tissue suspected of harboring melanoma cells. However, normal sun-damaged skin can look a lot like melanoma under the microscope. For example, its melanocytes (the pigment cells, where melanomas can develop) increase in number, density, and "confluence" (the tendency to come in contact with one another), much the way they do in melanomas. Unfortunately, guidelines for just how numerous, dense, or clustered melanoma cells are have been lacking, so physicians sometimes have had to make subjective judgments, removing some tissue that turns out to be normal.