HMGCR and breast cancer: Therefore, we used a CRISPR-CAS9 transcriptional activation system (CRISPRon) to determine whether HMGCR could act as a facilitator for the acquisition of stem-like states, considering: 1- MCF-7 cells expressed low levels of HMGCR; and 2- being a luminal BC cell model, MCF-7 contain a population of mostly epithelial tumor bulk cells with a low frequency of CSCs.