SURF4 and invasive ductal breast carcinoma: Moreover, high SURF4 expression was correlated with poor OS of breast cancer patients in infiltrating ductal carcinoma (P < 0.001), infiltrating lobular carcinoma (P = 0.018), luminal B type (P = 0.019), normal-like type (P = 0.016), ER negative (P = 0.003), PR negative (P < 0.001), and HER2 negative (P < 0.001) by subgroup analysis (Figure 4B–4N).