David Mandel is a writer on the Seinfeld crew. He worked with Peter Mehlman on “The Betrayal”. (On the DVD, Mandel and Mehlman do commentary for "The Betrayal". Mandel also does a brief introduction of "The Betrayal" when the viewer selects the feature that allows the episode to be viewed in normal chronology.) He appears as himself in “The Summer of George”, and he makes a voice cameo in “The Butter Shave”. When Jerry asks what the deal is with cancer, Mandel responds, “I have cancer!”