PTEN and breast cancer: A statistically significant association was observed between PTEN loss and TNM stage III–IV, with a pooled OR of 0.55 (95% CI = 0.35–0.86, P = 0.009 using a random-effects model; Figure 3C).In addition, a clear association was observed between PTEN loss and poorly differentiated breast cancer (OR = 0.37, 95% CI = 0.24–0.59; P < 0.0001 using a random-effects model; Figure 3D).