ERBB2 and breast cancer: Among these 33 breast cancer patients with exon 27 mutations, 9 patients were HER2 positive and the other 24 patients negative, 3 mutants were c.3430G>C p.D1144H, 3 mutants were c.3436C>T p.R1146W, 9 mutants were c.3574‐3576delGAG p.1192delE, 4 mutants were c.3662A>G p.Y1221C, 4 mutants were c.3688C>T p.R1230W, 5 mutants were c.3689G>C p.R1230P, 1 mutant was c.3725C>T p.T1242M, 1 mutant was c.3647C>A p.A1216D, and 3 mutants were c.3458G>C p.R1153Q.