ESRRA and cancer: Our results showed that mevalonate and cholesterol are able to activate the ERRα pathway, regardless of the subtype, promoting the expression of two main proteins: PGC-1α, an important co-activator of ERRα signaling, acting on mitochondrial biogenesis [55] and ERbB2/HER2, which is a tyrosine kinase receptor closely dependent on the ERRα pathway and implicated in cancer maintenance and progression [45,46].