Tmem201, also known as Samp1, is an integral inner nuclear membrane protein. It plays crucial roles in various biological processes such as endothelial cell migration, angiogenesis, and cell-cycle-relevant and immune-related pathways. It has been implicated in disease-related processes, including tumor progression in hepatocellular carcinoma and breast cancer [1,2,3].

In gene-knockout models, Tmem201-knockout mice showed arrested retinal vessel development and defective aortic ring sprouting, indicating its role in angiogenesis [1]. In zebrafish, loss of tmem201 impaired intersegmental vessel development, further validating its importance in vascular development [1]. In hepatocellular carcinoma, in vitro experiments showed that TMEM201 facilitated HCC proliferation, survival, and migration [2]. In breast cancer, TMEM201 promoted metastasis by positively regulating TGFβ signaling, as its deficiency inhibited epithelial-to-mesenchymal transition and TGFβ signaling [3].

In conclusion, Tmem201 is essential for endothelial cell-mediated angiogenesis and plays a significant role in promoting tumor progression in hepatocellular carcinoma and breast cancer. The use of gene-knockout mouse models and other loss-of-function experiments has been instrumental in revealing these functions, providing insights into the underlying mechanisms and potential therapeutic targets for related diseases.