IGDCC3 is an immunoglobulin superfamily cell adhesion molecule with roles in cell-cell adhesion and protein binding. IGDCC3 functions as a cell-surface marker enriched in phrenic motor neurons derived from human induced pluripotent stem cells, enabling fluorescence-activated cell sorting (FACS)-based enrichment of hiPSC-phMNs for disease modeling and research 1. This application demonstrates IGDCC3's utility as a selective marker for isolating specific neuronal populations relevant to studying amyotrophic lateral sclerosis and respiratory motor neuron dysfunction. IGDCC3 has emerging clinical significance in cancer biology. It was identified as a hub gene associated with cholangiocarcinoma progression and prognosis through weighted gene co-expression network analysis 2. Additionally, IGDCC3 expression is epigenetically regulated through enhancer-gene methylation patterns that distinguish CpG island methylator phenotype (CIMP) from non-CIMP colorectal cancers, with methylation of enhancer 1944 coordinately controlling IGDCC3 methylation status and potentially serving as a biomarker for CRC classification 3. IGDCC3 methylation is also associated with adipose tissue metabolic dysfunction in obesity, where differential methylation patterns correlate with metabolic inflammation and nicotinamide N-methyltransferase expression 4. These findings suggest IGDCC3 plays multifaceted roles in normal developmental processes and cancer biology through both protein function and epigenetic regulation.