CCR6 and non-small cell lung carcinoma: We also observed that the level of CCL20 mRNA expression decreased as smoking intensity increased, but increased the expression level of mRNA CCR6. Our study also showed a positive correlation between the expression level of CCR6 mRNA and the smoking status of patients with NSCLC (the lowest expression level of this gene was observed among non-smokers, subsequently higher in former smokers and the highest in current smokers).