Fang et al. demonstrated that four genes, i.e., Fc receptor-like A (FCRLA), Coiled-Coil Domain Containing 88C (CCDC88C), B-cell lymphoma 11B (BCL11B), and Apolipoprotein L6 (APOL6), are hypomethylated and down-regulated in RA compared with OA samples. Here, CCDC88C is linked to rheumatoid arthritis.