PSMB9 and breast cancer: We then analyzed the impact of ImP expression on OS, as well as bone, brain, liver, lungs, skin and lymph node metastasis, and found that a high frequency of PSMB8-expressing cells correlated with fewer patients with bone and liver metastases, and a trend to fewer patients with brain metastases (Fig. S5A, right panels), while PSMB9 expression had no significant correlations for all breast cancer patients together (Fig. S5B, left panel).