As indicated in Table 1, the mRNA level of PEX3 (p=0.0106 & p=0.0497), PEX12 (p< 0.0001) and PEX26 (p< 0.0001 & p=0.0005) was lower in ER & PR-positive BC compared to ER & PR-negative BC; contrariwise, the mRNA levels of PEX1/7/11A/11B/11G/12/19 (p< 0.0001), PEX2 (P=0.0106 & P=0.0212), PEX10 (P<0.0001 & P=0.0026) was lower in ER & PR-negative group compared to ER & PR-positive. This evidence concerns the gene ESR1 and breast cancer.