PPARGC1A and breast cancer: ERBB2/Neu-induced breast cancer cells with increased expression of PGC-1α (α-1.1) displayed two-fold enrichment or greater for PGC-1α and ERRα at the promoter of glutamine metabolism genes (Figure 1C), supporting the tight association between the ERRs and PGC-1 s in the control of metabolic genes [10,12].