Studies have reported an inverse relationship for the combination of ER+/PR+, ER+/PR-, ER-/PR- status and high PA, but not for moderate PA levels [7], whereas others have found stronger associations for ER- breast tumors [36,58], and an inverse relationship of PA with both ER+/- and PR+/- breast tumors [18,54,59,60]. This evidence concerns the gene PGR and breast neoplasm.