ERBB2 and breast cancer: The results of this study can be summarized as follows: (i) liver X receptor-retinoid X receptor (LXR/RXR) activation signaling, as a noval probable drug target specific for luminal A; (ii) NAD biosynthesis II pathway, as main potential drug target is exclusive in HER2 positive BC; and finally (iii) aryl hydrocarbon receptor signaling pathway, specific to basal like subtype (Cava et al., 2018).