MUC21 and non-small cell lung carcinoma: Considering that human airway located MUCs are possibly involved in the development of NSCLC, this study selected 19 human MUC genes (MUC1, MUC2, MUC3A, MUC3B, MUC4, MUC5AC, MUC5B, MUC6, MUC7, MUC8, MUC12, MUC13, MUC15, MUC16, MUC17, MUC19, MUC20, MUC21, and MUC22) that are highly abundant in the human airway for bioinformatics analysis based on the expression profiles of LUSC and LUAD patients.