ERBB2 and cancer: In accordance with the results described by Nagy et al. [33], and despite similar number of HER2 gene copies, the amount of accessible HER2 receptors at the surface of JIMT-1 cells (SABC ~53,800) appeared to be about 8 to 10-fold lower than that determined for the two HER2high cancer cells, due to overexpression of MUC4.