Although an increasing body of evidence supports the crucial role of the SEC24 Homolog D, COPII Coat Complex Component (SEC24D) gene in the initiation and progression of cancer, a comprehensive pan-cancer analysis of this gene is still lacking. In this study, we conducted an extensive investigation of SEC24D, aiming to elucidate its potential role and underlying mechanisms across multiple human tumors. Our analysis relied on data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. To validate our findings, we employed RNA sequencing (RNA-seq), targeted bisulfite sequencing (bisulfite-seq) molecular techniques. Our findings revealed elevated mRNA (Messenger RNA) and protein levels of SEC24D in different tumor tissues. However, the up-regulation of SEC24D was significantly correlated with shorter overall survival (OS), metastasis, and various clinical parameters in esophageal cancer (ESCA), lung adenocarcinoma (LUAD), and kidney renal papillary cell carcinoma (KIRP). Expression validation analysis via RNA-seq and targeted bisulfite-seq analyses, further confirmed the higher expression of SEC24D in LUAD cancer cell lines as compared to normal controls. The DNA methylation level of SEC24D was found to be decreased in ESCA, LUAD, and KIRP samples. DNA methylation analysis via bisulfite-seq analysis also validate the lower promoter methylation level of SE24D in LUAD cell lines relative to controls. Moreover, we observed a significant association between the elevated expression of SEC24D and the levels of infiltrating cells, such as B cells, neutrophils, macrophages, CD8+ T cells, and CD4+ T cells. Analysis of SEC24-related genes revealed that "Protein processing in endoplasmic reticulum, SNARE interaction in vesicular transport, Legionellosis, Pathogenic Escherichia coli infection" were mainly involved in the functional mechanism of SEC24D in ESCA, LUAD, and KIRP. Moreover, we also suggested a few valuable drugs (Acetaminophen, Acteoside, Cyclosporine, Polydatin, Estradiol, Estradiol, Quercetin) for treating ESCA, LUAD, and KIRP patients with respect to overexpressed SEC24D. To summarize, this comprehensive pan-cancer study investigated the association between SEC24D expression and clinical parameters in ESCA, LUAD, KIRP. The study provides valuable insights for further exploring the functional and therapeutic aspects of SEC24D and underscores its predictive significance in the carcinogenesis and prognosis of these specific cancer types.AJCR Copyright © 2023.