The genes listed in Table 1, which include phosphoglycerate kinase 1 (PGK1), syndecan 1 (SDC1, also known as CD138), syndecan 3 (SDC3), nucleoporin 43 (NUP43), interleukin 13 receptor subunit alpha 1 (IL13RA1), adenylate kinase 3 (AK3), and calcium voltage-gated channel subunit alpha 1H (CACNA1H), play a crucial role in the etiology of breast cancer. This evidence concerns the gene SDC1 and breast cancer.