Among cases with known PR status (n=68), 75% (n=51) of mammary tumors were positive. Among cases with known HER2 status (n=65), 93.8% (n=61) were negative, 4.6% (n=3) positive, and 1.5% (n=1) equivocal (Table 1). This evidence concerns the gene ERBB2 and breast cancer.