CYCS and cancer: NAF-144–67 selectively permeates through the PM of metastatic human epithelial breast cancer cells (MDA-MB-231), but not control epithelial cells (MCF-10A) and targets the mitochondria and ER membranes of cancer cells causing the release of cytochrome c and the activation of apoptotic and ferroptotic cell death pathways (only in cancer cells) [15].