PSMC4 and breast cancer: Furthermore, in the METABRIC database, expressions of PSMC members in breast cancer tissues were significantly higher than those in normal tissues; p values ranged from 2.16E-45 to 0.023 for PSMC1, 1.37E-29 to 0.016 for PSMC2, 3.18E-21 to 0.001 for PSMC3, 1.28E-53 to 0.018 for PSMC4, 7.02E-36 to 0.041 for PSMC5, and 9.03E-12 to 0.039 for PSMC6 (Supplementary Table 1).