The present invention relates to an isolated polypeptide capable of binding to and inhibiting the activity of the chemokine receptor CCR6 and to a method for identifying further inhibitors of CCR6 receptor activity. The present invention also relates to a method for detecting an interstitial lung disease or a cancer in a subject by determining the level of CCR6 gene expression in a sample from said subject and further provides pharmaceutical compositions comprising inhibitors of CCR6 receptor activity and/or expression for the treatment of said diseases.