PSMC6 and breast cancer: Of note, this does not exclude the possibility that other genes including UBB (Ubiquitin B), PSMC6 (Proteasome 26S subunit, ATPase 6), PEN1 (Penetration 1), HIST1H2BB (Histone Cluster 1 H2B Family Member B) would also play a role in the development of breast cancer.