Background Colorectal cancer (CRC) is one of the most prevalent malignant neoplasms. Tumor metastasis represents a significant contributor to unfavorable prognosis, and lung metastasis is the most common extra‐abdominal metastasis of CRC. However, pulmonary metastatic CRC has not received significant attention. Therefore, in this study, our main aim was to discover the key genes for lung metastasis and improve the prognosis of CRC. Methods Differentially expressed genes (DEGs) between primary tumors and patients with pulmonary metastatic CRC were obtained by analysis of a comprehensive database of gene expression (GEO). DEGs were screened by prognostic survival analysis, TCGA differential expression analysis, and single gene GSEA. Results Combining the differences in patient prognosis and expression, we found that CCL18 is a key gene in CRC lung metastasis. Macrophage coculture and transwell assay verified the potential of CCL18 in promoting the invasive metastatic ability of CRC cells, as well as the proliferation of CRC cells.
Xia et al. (Thu,) studied this question.