Rcn2, also known as reticulocalbin-2, is a protein-coding gene involved in multiple biological processes. It is associated with calcium-related pathways, as calcium release from the endoplasmic reticulum is related to its function. Dysregulation of Rcn2 is associated with various diseases, highlighting its biological importance [1,4,5]. Genetic models, such as gene knockout (KO) and conditional knockout (CKO) mouse models, can be valuable for studying its function.

In a mouse model of osteoarthritis (OA), chondrocyte-specific deletion of Rcn2 alleviated OA progression, while articular injection of Rcn2-expressing adeno-associated virus accelerated it. This indicates that Rcn2 promotes OA development, likely through promoting the phosphorylation and nuclear translocation of Stat3 [2]. In a model of sleep-related obesity, a hormone cleaved from Rcn2, named Raptin, was found to suppress appetite and obesity. Sleep deficiency impaired Raptin release, suggesting a link between Rcn2-derived Raptin and obesity [3].

In conclusion, Rcn2 is involved in multiple biological processes and disease conditions. Studies using KO/CKO mouse models have revealed its role in promoting osteoarthritis development and its association with sleep-related obesity. Understanding Rcn2's function can provide insights into the mechanisms of these diseases and potentially lead to new therapeutic strategies.