SATB1 and chronic mucus hypersecretion: Dijkstra et al. [30] conducted a genome-wide association study of habitual or former smokers (≥20 pack-years), with (n = 2,704) and without (n = 7,624) chronic mucus hypersecretion, reporting, for all cohorts, a strong association between chronic mucus hypersecretion and SNP rs6577641 located in intron 9 of the special AT-rich sequence-binding protein 1 locus (SATB1) gene on chromosome 3 (p = 4.25×10−6; OR = 1.17).