MDM4 and lung cancer: Mutations less than 10% comprehend also classical lung cancer related genes (EGFR, PDGFRA, NF1, KRAS, NTRK3, APC, GNAS, KDR, ERBB4 and EPHA5) and regulation of cellular processes (ERBB2, FGFR1, FLT4, RET, KIT, PTEN, PIK3CA, KDR, EPHB1, NOTCH2, TNFAIP3, AR, PTPRT, SMO, PTCH1, DICER1, PTPRZ1, CSMD3 and MDM4).