In conclusion, the functional characteristics of CSE-exposed CCR6+Th17 cells, both inflammatory and angiogenic, could contribute to the pathogenic potential of cigarette smoking in susceptible patients, as described for circulating angiogenic T cells in encephalomyelitis, systemic lupus erythematosus, systemic sclerosis and rheumatoid arthritis38,39. This evidence concerns the gene CCR6 and systemic sclerosis.