A positive correlation between the expression of HER3 and MET (Figure 1B) was noted in 24 human colon cancer cell lines (r = 0.54), but not in 25 breast and 22 lung cancer cell lines (r = 0.01 in breast cancers, and r = 0.27 in lung cancers) (data not shown). Here, ERBB3 is linked to breast cancer.