PGR and breast cancer: However, the overexpression of LIG1 was not significantly related to some BC subgroups, such as estrogen receptor-negative (ER-negative) (HR = 1.12, p = 0.32, Figure 3c), progesterone receptor-negative (PR-negative) (HR = 1.04, p = 0.81, Figure 3e) and human epidermal growth factor receptor 2-positive (Her2-positive) (HR = 1.17, p = 0.47, Figure 3f).