PPARGC1A and breast neoplasm: PGC-1α and PGC-1β were also reported to play a role in the resistance of ER-positive/tamoxifen-sensitive breast tumors.76 The interaction between PGC-1β and ERRα mediates a positive transcriptional regulation of receptor tyrosine-protein kinase (ERBB2) expression and co-amplifies genes associated with the ERBB2 amplicon.