ESRRA and cancer: As revealed by MTT assays, the suppressive effect of lapatinib on the viability of resistant cancer cells could be considerably attenuated (#P < 0.05, ##P < 0.01); after ERRα knockdown, the suppressive effects of lapatinib on non-resistant and resistant cells were both significantly enhanced (*P < 0.05, **P < 0.01) (Figure 2D).