In three (basal-like, ERBB2+ and luminal B) out of six subtypes of breast cancers, the expression levels of most of the RA-dependent upregulated genes are decreased and those of the ERK-dependent upregulated genes are increased, as compared to those in other subtypes (luminal A, normal breast-like and no subtype) (Figure 6C). Here, ERBB2 is linked to breast carcinoma.