It has not been established whether FAT1 plays a role in the pathogenesis of different tumors through some common molecular mechanisms; therefore, we performed a comprehensive pan-cancer analysis of FAT1 based on data in TCGA, CPTAC, and GEO from an overall tumor perspective, focusing on gene expression, gene alterations, protein phosphorylation, and prognosis. The gene discussed is FAT1; the disease is cancer.