the wild-type CYP2A6 allele, with an allele frequency of 2.2% reported among Spaniards [51]. CYP2A6*12 is shown to have reduced enzyme activity in vivo [55, 56]; in line with this, the minor allele of esv2663194 associates with decreased clearance rate. Further studies are needed to confirm whether the 32 kb deletion tagged by esv2663194 indeed creates a construct with properties similar to CYP2A6*12.
