Kristensen et al [5], studied the association between the tetranucleotide simple tandem repeat polymorphism and breast cancer risk in a case-control study (sporadic cases: n = 182; familial cases: n = 185; and controls; n = 252) among Norwegian and Swedish individuals and observed a positive association between carriage of the 12 repeat allele [allele [12], (TTTA)12] of CYP19 and risk of breast cancer compared with repeat lengths less than 12 (OR = 2.42, 95% CI, 1.03–5.80). The gene discussed is CYP19A1; the disease is breast cancer.