GSTP1 and breast cancer: Sacristan et al. indicated that methylation of RARB, CD44, GSTP1, IGSF4, CHFR, PYCARD, TP53, STK11 and GATA5 distinguished low-grade versus high-grade tumors, whereas Olkhov-Mitsel et al. stablished that the inclusion of GP5 and ZSCAN12 in a methylation panel could feasibly distinguish high-grade and low-grade BC (Olkhov-Mitsel et al., 2017).