ERA, ERB and PR detection in invasive ductal carcinoma. Rq (fold change) is the comparison of the expression in each individual tumor to the average of 7 benign tissues. Black bars indicate median values. ER positive (ER pos), or ER negative (ER neg) refers to IHC characterization by pathology. Delta Ct (dCt) values were calculated by subtracting the 18S rRNA Ct value from the target Ct value. Thus, dCt values are inversely related to gene expression (i.e. negative dCt values indicate high levels of gene expression).