ERBB2 and neoplasm: SOSTDC1 expression was inversely associated with tumor size (p = 0.037), grade (p = 0.019), ER status (p < 0.001), PR status (p = 0.001), and HER2 status (p = 0.007) (Table S1, Supporting Information), but positively associated with poor overall survival (OS) (p = 0.025) and poor relapse‐free survival (RFS) (p = 0.0043) of TNBC patient (Figure 1E).