Usp22, short for ubiquitin specific peptidase 22, belongs to the ubiquitin-specific protease (USP) family of deubiquitinases (DUBs). Its main function is to remove ubiquitin chains from substrates, thereby altering the substrates' biological activity. Usp22 is involved in various physiological and pathological processes, such as cell cycle, proliferation, apoptosis, and immunity [3].

In multiple disease-related studies, gene-knockout models have provided significant insights. In hepatocellular carcinoma (HCC), Usp22-targeting lipopolyplexes caused high tumour inhibition and high sorafenib sensitivity in mice bearing HCC, showing its potential as a therapeutic target for HCC [1]. In colorectal cancer, knocking down Usp22 enhanced the therapeutic efficacy of EZH2 inhibitors [2]. In endometrial stromal cells, knockdown of Usp22 led to a reduction in cell proliferation and decidualization [4].

In conclusion, Usp22 is a crucial regulator in multiple biological processes. Model-based research, especially through gene-knockout mouse models, has revealed its significance in diseases like HCC, colorectal cancer, and endometrial-related conditions. These findings suggest that Usp22 could be a potential target for therapeutic intervention in these disease areas.