Another contributing mechanism to this phenomenon involves the EGFR axis: scRNAseq revealed that amphiregulin expression is significantly increased in IPF-ABCs compared to NU-ABCs and that the bronchospheres generated from IPF-ABCs secrete significantly higher concentrations of amphiregulin compared to both HV-ABCs and NU-ABCs. Here, AREG is linked to idiopathic pulmonary fibrosis.