Clmn, also known as calmin, is an ER-enriched actin-binding protein that functions as an ER-actin tether localizing to focal adhesions adjacent to ER tubules [2,4]. It is involved in processes like cell cycle regulation and cell migration. In the cell cycle, it participates in G(1)/S arrest, and in cell migration, it promotes this process by facilitating focal adhesion disassembly, actin dynamics, and calcium signaling near adhesions [2,3,4]. It also has associations with the cell cycle process in breast invasive carcinoma [1].

In murine neuroblastoma (Neuro2a) cells, knockdown of Clmn nearly eliminates the reduction in cell proliferation and neurite outgrowth induced by all-trans retinoic acid (atRA), indicating that Clmn is required for atRA-mediated cell cycle exit and neurite outgrowth [3]. In breast invasive carcinoma, CLMN mRNA high expression is conducive to the overall survival of patients, and pathway analysis suggests it mainly participates in the cell cycle process and exerts an inhibition effect on the cell cycle involved in this cancer [1].

In conclusion, Clmn is essential for cell cycle regulation, cell migration, and neuronal differentiation. Its role in diseases such as breast invasive carcinoma and its requirement for atRA-mediated processes in neuroblastoma cells highlight its importance in understanding disease mechanisms. These functions have been revealed through functional studies including loss-of-function experiments in cell models, providing insights into potential therapeutic targets related to cell cycle-related diseases and neuronal development disorders.