The epigenetic mechanisms in regulation of genes' expression seem to be another 
field of research that gains land in genetic association studies of rheumatoid 
arthritis (RA) susceptibility factors. Recently, a new class of molecules has 
been discovered, the microRNAs (miRNAs). miRNAs are related to 
post-transcriptional regulation of genes' expression. Different expression 
patterns of mir-146a, miRNA-155, miRNA-124a, mir-203, mir-223, mir-346, mir-132, 
mir-363, mir-498, mir-15a, and mir-16 were documented in several tissue sample 
types of RA patients. The polymorphisms of these miRNAs and their gene targets, 
which previously have been associated with RA or other autoimmune diseases, are 
also reviewed. Finally, using web-based tools we propose polymorphisms of the 
discussed miRNAs and their gene-targets that worth to be studied for their role 
in RA predisposition.