MT1M and rheumatoid arthritis: MT-1M expression was significantly reduced by the simultaneous exposure to Cd and Zn in RA cells compared to the Cd-alone condition (reduced fold change from mean ± SD 57.95 ± 15.53 to mean ± SD 18.75 ± 9.77, p<0.05), only in cytokine unstimulated RA cells.