ESR1 and breast cancer: SRC/GSTP1 expression and G6PDY249/322 phosphorylation were positively correlated in breast cancer tissues characterized to be ER (+) and PR (+) or HER (-); however, this correlation was not evident in ER(-)/PR(-) or ER(-)/PR(+) or HER (+) tumor tissues (Fig. 6D, Fig. S6B).