Fig. 1

a Cell viability of MCF7/EVC and MCF7/PGRMC1 cells as well as MDA-MB-231/EVC and MDA-MB-231/PGRMC1 cells (n = 3). Viability was analyzed by MTT assay at t = 0 h, 24 h, 48 h, 72 h, and 96 h/37 °C. Values were normalized to t = 0 (100%). *p ≤ 0.05, **p ≤ 0.01 (Student’s t test, n = 3). b Cell viability of MCF7 and MDA-MB-231 cells, treated with siRNA against PGRMC1 (siPGRMC1) and scrambled siRNA (siControl) (Student’s t test, n = 3). Viability was analyzed at t = 0 h, 24 h, 48 h, and 72 h/37 °C. Values were normalized to t = 0 (100%). *p ≤ 0.05, **p ≤ 0.01 (Student’s t test, n = 3). c Tumor volumes of immunodeficient mice bearing human breast cancer MCF7/EVC and MCF7/PGRMC1 xenografts. ***p ≤ 0.001, ****p ≤ 0.0001 (Student’s t test, n = 11 mice each group). Images of tumor tissue dissected from each mouse