Ctsg, also known as Cathepsin G, is a member of the serine proteases family. It plays a role in multiple biological processes, such as regulation of immune processes, and is involved in the generation of Angiotensin II within the renin-angiotensin system, which regulates blood pressure and fluid-electrolyte homeostasis [2,3]. It can increase the permeability of vascular endothelial cells and the chemotaxis of inflammatory cells, and may be related to the infiltration of muscle inflammatory cells [4].

In colorectal cancer, Ctsg acts as a tumor suppressor gene. Overexpression of Ctsg suppresses CRC cell progression in vitro and in vivo by negatively regulating the Akt/mTOR/Bcl2 anti-apoptotic signaling pathway, while its suppression promotes CRC development [1].

In Chinese children with type 1 diabetes mellitus, the CTSG rs2236742 allele (C/T) is associated with T1DM, and CTSG expression is significantly higher in patients compared to the control group [2].

In dermatomyositis, the expression and activity of Ctsg are increased, and it may be involved in muscle inflammatory cell infiltration [4]. Also, in the development of chronic postsurgical pain, Ctsg is up-regulated and acts as a pronociceptive mediator, and specific genotypes at polymorphisms rs2070697 or rs2236742 in the CTSG gene are associated with a lower risk of chronic postsurgical pain [5].

In conclusion, Ctsg is involved in various biological functions and disease conditions. Its role as a tumor suppressor in colorectal cancer, its association with type 1 diabetes mellitus, its involvement in dermatomyositis, and its role in chronic postsurgical pain have been revealed through relevant studies. Understanding Ctsg can provide insights into the mechanisms of these diseases and potential therapeutic targets.