Another polymorphic gene with potential relevance in breast cancer development is NPAS2. A first case-control study on non-synonymous polymorphisms rs2305160 Ala394Thr of NPAS2, among 431 breast cancer women and 476 controls (most of them were Caucasians) has revealed that rs2305160 Ala/Thr genotype had a significant association with a decreased breast cancer risk in comparison to more frequent Ala/Ala genotype (OR = 0.61 95% CI = 0.46–0.81) [13]. Here, NPAS2 is linked to breast cancer.