MDM2 and psoriasis: Interestingly, mutations of MDM2 enhance transcription of p53 target genes, suggesting that MDM2 also regulates p53 activity at the transcriptional level.[31] To investigate the mechanism by which FGF12 regulates the p53 signaling pathway in psoriasis and keratinocytes, we assessed the protein levels of p53 and p21 in keratinocytes overexpressing FGF12 in the presence or absence of si‐MDM2.