We present a 47-year-old Asian male with Hermansky-Pudlak syndrome-associated pulmonary fibrosis (HPS-PF), a congenital right-sided aortic arch, and a MUC5B mutation-an exceptionally rare case of multifactorial pulmonary fibrosis complicated by lung cancer. The gene discussed is MUC5B; the disease is pemphigus foliaceus.