PDF and xeroderma pigmentosum: As for the 12 genes whose expression in RNA-seq was different from the PCR array data (KLK10, KLK6, HRH4, C9, F8, F12, PDGFA, HRH2, KLK14, PDF, KLK5, KLK12), we speculate that their altered expression was related to the bad survival rate upon tumor development in XP patients.