NPAS2 and breast cancer: Kovanen et al. [46] showed that women with BMAL1 rs2278749 TT genotypes had more pregnancies and miscarriages, whereas NPAS2 rs11673746 T carriers had fewer miscarriages, indicating a possible role of these polymorphisms affecting age at first birth and also number of children, both of which are established risk factors for breast cancer [58].