Can a simple cream shield transplant patients from skin cancer?

This study is testing whether a daily cream containing 5% niacinamide (a form of vitamin B3) can help prevent skin cancer in people who have received an organ transplant. Transplant recipients take lifelong medications that suppress their immune system, which makes them much more likely to develop skin cancers. The trial will compare the cream plus sunscreen to sunscreen alone over 12 months to see if it reduces precancerous spots and new skin cancers.