Fig. 1

Characterization of ZR-75-1 as an HR+/HER2-low breast cancer cell line. (A,B) Heat maps of gene expression in PAM50 cells of different breast cancer subtypes and heat maps of ERBB2 expression in HR+/HER2- breast cancer cells. (C) HER2 expression in HR+/HER2-0 and HR+/HER2-low breast cancer subtypes by cellular immunofluorescence assay. (D) HER2 levels in HR+/HER2-0 and HR+/HER2-low breast cancer subtypes measured with ImageJ, P = 0.029. (E) HER2 expression in HR+/HER2-0 and HR+/HER2-low breast cancer subtypes by fluorescence quantitative PCR assay, P = 0.015, *P < 0.05; n = 3.