CRIM1 (cysteine-rich transmembrane BMP regulator 1) is a developmentally regulated transmembrane protein that modulates bone morphogenetic protein (BMP) activity by regulating BMP processing and cell surface delivery 1. The protein contains cysteine-rich repeats and an IGF-binding protein motif 2, enabling interaction with multiple growth factors including TGFβs, BMPs, VEGFs, and PDGFs 3. CRIM1 plays pleiotropic roles during embryogenesis, with expression in notochord, somites, floor plate, and motor neurons during CNS development 2. It regulates organogenesis in the eye, kidney, placenta, and heart 3. CRIM1 haploinsufficiency causes macrophthalmia with microcornea (MACOM) syndrome, an autosomal dominant eye malformation characterized by microcornea, coloboma, and myopia 4. Mouse models demonstrate that reduced Crim1 expression impairs lens epithelial cell development and cell adhesion 5. Beyond ocular development, CRIM1 dysregulation is implicated in multiple pathological conditions. Increased CRIM1 expression occurs in hypoplastic left heart syndrome cardiomyocytes 6, while decreased expression associates with reduced polycystic ovary syndrome risk 7. CRIM1 is also dysregulated in LMNA-associated dilated cardiomyopathy, where it correlates with disease severity 8. Its role in angiogenesis and EMT regulation suggests involvement in cancer progression 1.