The xenograft models were developed using 4–6-week-old CD1-Foxn1nu nude male mice and subcutaneously inoculating HNSCC cell lines, i.e., Cal27. In each mouse, the left flank received Cal27 untreated cells and the right flank received Cal27 Cornulin-overexpressing cells to allow within-animal comparison. After tumor development, mice were sacrificed, and xenograft tumors were excised. Tumor tissues were then subjected to protein extraction, tryptic digestion, and LC-MS/MS-based proteomic analysis to identify differentially expressed proteins associated with Cornulin overexpression in vivo.