A comparison of the middle ear mucosa of the non-otitis media group, COM group, and chronic suppurative otitis-media (CSOM) group showed no difference in mRNA or protein levels of TLR2 between the non-otitis media and COM groups, but revealed a significant reduction in TLR2 expression in the CSOM group. The gene discussed is TLR2; the disease is chronic purulent otitis media.