ERBB2 and breast cancer: Interestingly, TENM4 mRNA up-regulation was not restricted only to TNBC tumorsphere-derived cells but was also evident in tumorspheres from MCF-7 (human ER+) and SK-BR-3 (human Her2+) breast cancer cell line (Figure S3a), confirming a potential role of TENM4 not only in TNBC but also in other breast cancer subtypes.