The estrogenic effects in the PC3 xenograft mice were proposed to occur through the activity of ERα, and its interaction with the estrogen response elements in the MMP12 gene, regulating the expression of matrix metalloproteinase 12 (MMP-12) [193], a family member of a class of proteins (MMPs) involved in the remodeling of extracellular matrix, tumor progression, and metastization [194,195]. The gene discussed is ESR1; the disease is neoplasm.