In the breast cancer validation dataset, only PSMA4 (HER2/ER- subtype, n = 2; bilateral breast cancer), PSMB7 (Luminal B/HER2- subtype, n = 1), PSMD3 (Luminal B/HER2- subtype, n = 3; Luminal B/HER2 + subtype, n = 1; Basal-like subtype, n = 1), and PSME4 (Luminal B/HER2- subtype, n = 2) harbored mutations. This evidence concerns the gene PSME4 and breast cancer.