ERBB4 and neoplasm: Gene expression data for three-fourths of the HER family of receptors (EGFR, HER2, HER4), some of their ligands (TGFA, EGF, AREG), as well as other pathway components including MEK1, MEK2, PIK3CA, PIK3R1, CRYAB, AKT1-3, the RAS proteins (H, K and N), ERK1, ERK2, and a KRAS-amplicon signature (identified and defined in Herschkowitz et al. [35]), were individually tested for the ability to predict patient outcomes, for correlations with tumor subtype (Table 4), and for correlations with the EGFR-associated expression Clusters #1–3 (Table 5).