EGFR and breast cancer: Even though UCHL1 negatively regulates ER expression through the stabilisation of EGFR and subsequent hyperactivation of MAPK signalling, direct EGFR and/or MAPK silencing or inhibition were not explored by Chen et al. to elucidate their effects on ER expression and endocrine therapy in breast cancer cell lines with modulated UCHL1 expression [41].