Cell adhesion molecules (CAM) mediate cell to cell interactions in various body systems including the immune system. The four major families of CAMs include immunoglobulin (Ig) superfamily, cadherins, integrins, and selectins. Most interestingly, several CAMs have emerged in recent years as leading biomarkers of lupus nephritis (LN) based on comprehensive proteomic screens of urine. Proteins belonging to all four families of CAMs have been reported to be upregulated in LN urine. Belonging to the Ig superfamily are the following elevated proteins: ALCAM, VCAM-1, BCAM, EpCAM, NCAM-1, NCAM-120, NrCAM, OBCAM, PECAM-1, sICAM-1, sICAM-2, and sICAM-5. Similarly, cadherins such as P-Cadherin, Cadherin-5, Cadherin-2, Cadherin-12, and E-Cadherin, integrin family members integrin avb5, integrin a1b1, fibronectin, and GP1BA, as well as multiple selectins including L-selectin, E-selectin, and P-selectin have all been reported to be upregulated in LN urine. These findings and the documented interactions between these proteins and their ligands suggest that “sticky interactions” between various immune cells mediated by CAMS may play key pathogenic roles in this disease.