ERBB2 and neoplasm: Interestingly, when the same oncogenic hit was overexpressed in LCs (Krt8-expressing cells) or BCs (Lgr5-expressing cells), the resulting tumors were basal-like, HER2-positive, and luminal B (Krt8-derived tumor), or mainly luminal A and B (Lgr5-derived tumors) [43] (Figure 4).