Acanthosis nigricans (AN) is a common skin disorder characterized by darkened, thickened, velvety plaques that most often develop in body folds such as the neck and underarms. The 12-week study enrolled five adult participants, all of whom applied sirolimus gel 0.2% twice daily to the affected area. Disease severity improved by 30.2%, with significant reductions in Acanthosis Nigricans Scoring Chart (ANSC) scores. The researchers concluded that sirolimus gel 0.2% appears to be a promising topical treatment for acanthosis nigricans, offering early improvements in pigmentation, skin texture, and patient-reported outcomes with minimal side effects. Evaluating the Safety and Efficacy of Sirolimus Topical Gel 0.2% to Treat Acanthosis Nigricans.