Transcriptional activation occurs via autoregulation [56] and other transcription factors such as NF-κB (nuclear factor κB) [57], AhR (aryl hydrocarbon receptor) [58], PPARγ (peroxisome proliferator-activated receptor γ) [59], p53 [60], MEF2D (myocyte enhancer factor 2d) [61], c-Jun, c-Myc [62] and BRCA1 (breast cancer 1) [63], through binding to ARE- and XRE (xenobiotic response element)-like elements in its promoter region. The gene discussed is MEF2D; the disease is breast cancer.