Based on limited published evidence, NICOL1 is an mRNA-binding protein that stabilizes target mRNAs including SERPINE1, ACTA2, CCN2, and COL4A1, potentially promoting extracellular matrix production. It binds 3'-UTR regions and may prevent SERBP1-mediated degradation. NICOL1 functions as a testis-derived lumicrine factor regulating epididymal differentiation and sperm maturation. Recent single-cell RNA sequencing identifies NICOL1 as a gatekeeper of trophoblast stem cell state during placental development 1.