SP1 and lung cancer: Mechanistically, CSC induces ZFAS1 expression via SP1 and NFĸB-associated activation of an enhancer linked to ZFAS1. Subsequently, ZFAS1 interacts with DNA methyltransferases and polycomb group proteins to silence ZNFX1. Mithramycin and methysticin repress ZFAS1 and upregulate ZNFX1 in lung cancer cells in vitro and in vivo.