LRPAP1 and rheumatoid arthritis: In pathway analysis of these overlapping epigenetic variants, one of the top ranked pathways was associated with low-density lipoprotein receptor activity (p = 0.003), which associates closely with the protein produced by the LRPAP1 gene, the methylation of which was recently reported as a potential biomarker of anti-TNF treatment response in RA patients [38].