Expression and roles of steroidogenic acute regulatory (StAR) protein in 'non-classical', extra-adrenal and extra-gonadal cells and tissues

► 'Non-classical' StAR facilitates steroidogenesis or other mitochondrial activities. ► Steroidogenic StAR affects development and protects against cytotoxic insults. ► In transformed cells, steroidogenic StAR allows escape from tumor immunity. ► StAR can enhance bile acid production and synthesis of regulatory oxysterols. ► StAR can also confer anti-apoptotic robustness and chemotherapy resistance.