FREM1 expression is reduced in tumor tissues, which is associated with poor survival. (A) Representative IHC staining of FREM1 in human primary tumor and adjacent non-tumor tissue. Magnifications: 4X; boxed area is 40X. Scale bar: 4X, 200 μm; 40X, 20 μm. (B) FREM1 level is higher in adjacent tissues than in tumor tissues. Magnifications: 4X; and boxed area is 40X. Scale bar: 4X, 200 μm; 40X, 20 μm. (C, D) Analysis of FREM1 IHC staining scores in adjacent non-tumor (n = 48) and tumor tissue (n = 56). (*P < 0.05, **P < 0.01, ***P < 0.001). (E–H) Survival curves of OS and DFS in breast cancer and HER2 with low and high FREM1 expression. Median survival time of the high-expression group versus low-expression group.