We compared the expression levels of γ-secretase subunits in the sample group of triple negative breast cancer cases (N = 10) to the expression in cancer tissues expressing at least one of the receptors ER, PR, or Her2 and found a significant association with PS2 (p = 0.002; Table S4), Aph1a (p = 0.038; Table S5), Aph1b (p = 0.002; Table S6), and PEN-2 subunits (p = 0.025; Table S7). Here, APH1A is linked to triple-negative breast carcinoma.