Although overlap with GPA was initially suspected due to strong PR3-ANCA positivity and ENT involvement, the subsequent evolution with recurrent mucocutaneous ulcers, ocular inflammation, catastrophic gastrointestinal perforations, thromboembolic events, and cardiac involvement was more consistent with severe BD, leading to the interpretation of this case as PR3-ANCA positive BD rather than a true overlap. The gene discussed is PRTN3; the disease is inflammation.