Moreover, the stabilization of SMAR1 was more prominent in highly metastatic breast cancer cell lines MDA-MB-231 (Triple negative breast cancer, Basal B), NCI-ADR-RES (Luminal A-metastatic) and T47D (Luminal A), than in MCF7 (Lower metastatic, luminal A) (Supplementary Figures 1a and b) following treatment with MG132.22, 23, 24 The cycloheximide pulse chase assay provided additional evidence that SMAR1 is regulated at the proteasomal level (Figure 1b). Here, BANP is linked to breast cancer.