PSMD2 and breast cancer: A variety of genes encoding the proteasome subunit have been found to be up-regulated in various tumors.157, 158, 159, 160 In 2007, Deng et al analyzed the difference in proteasome genes between breast cancer tissues and normal tissues by RT-PCR and found that several 26S particle subunits coding genes were up-regulated, including PSMB5, PSMD1, PSMD2, PSMD8, and PSMD11.161