First, we compared proteasome beta subunits (PSMB1-10) gene expression in breast cancer with other malignant tumors using data for 19,145 patient samples from 144 datasets covering 20 cancer types (R2: Genomics Analysis and Visualization Platform, http://r2.amc.nl, accessed 5 March 2024) and analyzed BC cell lines dependency on gene expression (from DepMap data) using a pipeline published previously [41]. The gene discussed is PSMB1; the disease is breast cancer.