Olfm2, also known as noelin 2, is a pleiotropic protein belonging to the olfactomedin domain-containing protein family. It plays significant roles in multiple biological processes, including olfaction, energy homeostasis, and is involved in several disease-related pathways such as TGF-β/Smad signaling pathway [1,2]. Gene knockout (KO) mouse models are valuable tools for studying Olfm2's functions.

In KO mouse models, global lack of Olfm2 promoted anorexia and increased energy expenditure due to elevated brown adipose tissue thermogenesis and browning of white adipose tissue, leading to resistance to high-fat diet-induced obesity [2]. In the context of colorectal cancer, knockdown of Olfm2 inhibited migration and invasion of colon cancer cells, with E-cadherin expression increasing while N-cadherin and Vimentin expression decreasing, and it also reduced TGF-βR1 and downstream molecules p-Smad2 and p-Smad3 related to the TGF-β/Smad pathway [1].

In conclusion, Olfm2 is crucial in regulating energy homeostasis and plays a role in the progression of colorectal cancer. The Olfm2 KO mouse models have provided insights into its functions in obesity and cancer, highlighting its potential as a diagnostic and therapeutic target in these disease areas.