Using in situ hybridization, the researchers compared the expression of 8 mucins (MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, MUC6, MUC7, and MUC8) in nasal polyps and normal sphenoid sinus mucosa. This evidence concerns the gene MUC5AC and nasal cavity polyp.