Snd1, also known as Tudor-SN, TSN or p100, encodes an evolutionarily conserved protein. It contains four staphylococcal nuclease domains and a Tudor domain, endowing it with endonuclease activity and the ability to interact with nucleic acids, proteins and protein complexes. Snd1 plays fundamental roles in gene expression regulation, including RNA splicing, interference, stability, and editing, as well as in protein and lipid homeostasis. It has drawn attention as a potential disease biomarker, especially related to cancer progression [2].

In prostate cancer mouse models (PB-Cre/Ptenflox/flox/ERG mice), prostate-specific Snd1 deletion reduces cancer growth and tumor burden. Knocking down Snd1 in human prostate epithelial cells, especially those overexpressing ERG, negatively impacts cell proliferation, highlighting Snd1's crucial role in prostate tumorigenesis [3]. In SARS-CoV-2 infection, Snd1 binds the 5' end of negative-sense viral RNA. Snd1-depleted cells form smaller replication organelles and display diminished virus growth kinetics, indicating its role in promoting viral RNA synthesis [1].

In conclusion, Snd1 is essential in multiple biological processes, especially in gene expression regulation and lipid metabolism. Model-based research, such as the use of gene-knockout mouse models in prostate cancer, reveals its significant role in cancer development. Also, its function in promoting SARS-CoV-2 RNA synthesis shows its importance in viral infections. Understanding Snd1 contributes to unravelling disease mechanisms and developing potential therapeutic strategies.