Comparing the low and high expression levels of FREM1 by Kaplan-Meier survival analysis in breast cancer and the HER2 subtype. (A–D) Survival curves of OS and DFS in breast cancer and HER2 from the TCGA database. (E–H) Survival curves of OS and DFS in breast cancer and HER2 from the GEO database. OS, overall survival; DFS, disease-free survival.