MUC5AC and congenital rubella syndrome: Compared with normal nasal mucosa, the expression of MUC3 and MUC6 in nasal polyps is downregulated, the expression of MUC2 and muc8 in nasal polyps is upregulated, the expression of MUC5AC and MUC5B in CRS is upregulated, and the expression of MUC5AC in nasal polyps far exceeded MUC1 and MUC2.