BRCA1-defective human breast cancer, HCC1937 cells (a BRCA1 mutation with an insertion of C at nucleotide 5382, and a negative expression of HER2/neu, and estrogen receptor α (ERα)) were significantly more sensitive to cisplatin than BRCA1 reconstituted cells with a full-length cDNA transfection [39]. This evidence concerns the gene ERBB2 and breast cancer.