PPARD and melanoma: In melanoma cell lines with high metastatic potential, activation of PPARβ/δ causes upregulation of Snail and increased sensitivity to signaling stimuli for migration and invasion, where Snail acts as a transcription factor to inhibit E-cadherin transcription in epithelial cells, a phenomenon that can be reversed by inhibition of PPARβ/δ (Ham et al., 2014).