Ten or more cytoplasmic mucin inclusions in a tissue microarray core were seen in 51%, 48% and 31% of the 416 adenocarcinomas and 3%, 4% and 0.5% of the 194 squamous cell carcinomas with PASD, ABPAS and mucicarmine, respectively. The gene discussed is MUC5AC; the disease is squamous cell carcinoma.