Emp1, encoding epithelial membrane protein 1, belongs to the peripheral myelin protein 22-kDa (PMP22) gene family [2]. Its functions seem to be related to cell proliferation, migration, and metastasis, and it may be involved in multiple signaling pathways like RAS/RAF/MAPK [4]. It has significance in various biological processes including cancer development and liver fibrosis [2,6]. Genetic models can be crucial for studying its functions.

In colorectal cancer, genetic ablation of EMP1high cells (using Emp1 as a marker gene for high-relapse cells) in a human-like mouse model prevented metastatic recurrence, suggesting Emp1-positive cells drive metastatic relapse [1]. In bladder cancer, loss of Emp1 promoted cell migration and resistance to ferroptosis through activation of PPARγ signaling [3]. In osteosarcoma, knockdown of Emp1 inhibited migratory and invasive abilities of cells, indicating Emp1 promotes the malignant progression of osteosarcoma through the IRX2/MMP9 axis [5].

In conclusion, Emp1 is significantly involved in the metastasis and progression of multiple cancers such as colorectal, bladder, and osteosarcoma. Gene-knockout studies in mouse models have been instrumental in revealing its role in cancer-related biological processes, providing potential therapeutic targets for these diseases.