ERBB2 and breast cancer: As a result, the increased CADM3 level in BC was considerably related to ER (P < 0.05; Fig. 4A), PR (P < 0.01; Fig. 4B), HER2 (P < 0.001; Fig. 4C) expression status, age (P < 0.01; Fig. 4D) and PAM50 (P < 0.001; Fig. 4E).