To determine the key molecule participating in the peritoneal mesothelial fibrosis, differentially expressed genes of HMrSV5 cells in mono-cultured and co-cultured with HOXA11 over-expressed GC cells or its counterparts were selected and the expression changes in the RNA-sequencing profiling data were validated by Western blotting, qRT-PCR, and immunohistochemistry assays. This evidence concerns the gene HOXA11 and gastric cancer.