A 49-year-old man notices a painless rash on his shoulder but doesn’t seek care. Months later, during a routine physical, his doctor notices the rash and diagnoses it as a benign skin condition. More time passes, and during a routine screening test, a nurse points out the rash to another physician who urges the patient to see a dermatologist. A dermatologist performs a biopsy of it. The pathology report reveals a noncancerous lesion. The dermatologist seeks a second reading of the pathology slides. This time, a drastically different verdict: invasive melanoma. The patient is immediately started on chemotherapy. Weeks later, a physician friend asks him why he’s not on immunotherapy instead.