MUC5B and idiopathic pulmonary fibrosis: The SCGB1A1+MUC5B+ club cells from IPF patients expressed mucin (SPDEF, MUC5B, TFF3, and AGR2) and chemoattractant cytokines for immune cells (CXCL1, CXCL6, CXCL8, and CX3CL1).