ERBB2 and breast cancer: Ntf3 and its receptor Ntrk3, though they do not identify a canonical pathway, are overexpressed in a significant proportion of human breast cancers, particularly in basal-like breast cancers (11 % amplified + upregulated in basal-like PAM50 breast cancers vs. 5 % in all breast cancers, 6 % in luminal A/B, and 0 % in Her2+) [24, 25].