NRF1 and hepatocellular carcinoma: Transmembrane protein 27 (CLTRN, also known as TMEM27) is a type Ia transmembrane (Akpinar et al., 2005), which can be regulated by the Nrf-1/RAN/DLD protein complex to deplete GSH and enhance the radiosensitivity of hepatocellular carcinoma (HCC) cells (Yuan et al., 2021).