Cell culture
The SKBR-3 cell line was obtained from the American Type Culture Collection (Manassas, VA), while MDA-MB-231 cells were a kind gift of Peter Bay (University of Debrecen). The cell lines were selected based on their different atorvastatin sensitivity (Göbel, Breining, Rauner, Hofbauer & Rachner, 2019; Kimbung, Lettiero, Feldt, Bosch & Borgquist, 2016; Zhang et al., 2019). Both cell lines were propagated in DMEM containing 10% fetal bovine serum supplemented with antibiotics. Cells were harvested at a confluency of 80-90% before measurements.