It is extremely interesting that 3 BC-associated SNPs, c.-1607 2G > 1G (rs1799750) MMP1, c.2003 G > A (rs17577) MMP9, and c.-1562 C > T (rs3918242) MMP9, and 12 loci linked to the last 2 SNPs are eSNPs (MMP1, SNX21, SLC12A5) in BC target organ: the mammary gland (Supplementary Tables S7 and S8). This evidence concerns the gene SNX21 and breast cancer.