RAD21 expression correlated with larger tumor size (P = 0.012) and lymph node involvement (P < 0.001), but not with tumor grade (P = 0.328), age (P = 0.815), HER2 status (P = 0.564) or ER status (P = 0.054) (Table 3). This evidence concerns the gene ERBB2 and neoplasm.