GPX3 rs8177447 (p=0.014, padj =0.035) and SELS rs4965814 (p=0.046, padj =0.06) were significant among individuals of <28% NA ancestry; SEPP1 rs230812 (p=0.025, padj = 0.04), and SEPP1 rs6865453 (p=0.002, padj = 0.005) were associated with breast cancer risk in individuals of 28-70% NA ancestry; and SEPN1 rs718391 (p=0.02, padj =0.09) was marginally associated with breast cancer risk among women of >70% NA ancestry. This evidence concerns the gene SELENOS and breast cancer.