PSMB9 and breast cancer: Among them, seven genes (JUN, FOS, FOSB, EGR1, ZFP36, CFD, and PPARG) were downregulated in BC compared to normal tissues, and in aggressive BC (basal, HER2+, and luminal B), TP53 mutation group, younger patients, higher stages, and lymph node metastasis, while CD27, PSMB9, and SELL were upregulated, suggesting that these candidate genes could be indicators of aggressive types of BC, like HER2+ and TNBC, and might be responsible for the characteristics of invasive BC.