To study the effect of bASCs and their secreted cytokines, spheroids were generated with two luminal B breast cancer cell lines BT474(ER+, PR+, HER2+) and MDA-MB-361(ER+, PR+/−, HER2+) [27] and seeded on a bASC feeder layer as indicated in Fig. S3E. Area and diameter of spheroids were measured up to 96 h. This evidence concerns the gene ERBB2 and breast cancer.