(A,B) Gene ontology (GO) terms related to the biological process (BP) category were assigned to genes associated with CEACAM5 and MDM2 based on HNSCC transcriptome-sequencing data. (C,E) The expression of CEACAM5 and MDM2 in normal and HNSCC tissues was analyzed based on data from TCGA. (D) Correlation analysis between MDM2 and CEACAM5 in HNSCC tissues based on data from TCGA (n=455). (F,G) The expression of MDM2 in HNSCC cells after stable lentivirus-mediated transduction was assessed by qRT-PCR. (H) PPI analysis was performed on genes related to the roles of CEACAM5 and MDM2 in HNSCC. (I) The mRNA expression levels of MDM2 in xenograft-derived tumors in nude mice were measured by qRT-PCR. (J) The protein expression of MDM2 in HNSCC cells was assessed by WB. The relevant statistics are shown in the right panel. *P<0.05, **P<0.01, ***P<0.001.