NDRG1 and breast cancer: Based on the meta-analysis of three studies, there was a negative correlation between NDRG1 protein expression and Her2 status (P = 0.01, log OR: -0.76, 95% CI: -1.32-(-0.20), I2: 32.42%, 197 breast cancer with Her2 positive/272 breast cancer with Her2 negative, 3 studies, Fig. 8).