Our study also allowed to identify probable players in the adaptation of MCF7 cell line to the studied media, i.e., TP63, HEY1, TBX3 and PGR. Although it has been observed, that high expression of p63 protein is characteristic to breast cancer cells with basal-like features [35], in this study MCF7 cell line was characterized by the highest expression of TP63 as compared to the other studied cell lines. The gene discussed is HEY1; the disease is breast cancer.