Thus, TM4SF5-induced CD44v8-10, but not CD44s, can form a complex with the xc− system, presumably within T5ERMs, leading to a TM4SF5-mediated increase in cystine uptake and cellular antioxidant GSH levels for hormetic ROS modulation during idiopathic pulmonary lung fibrosis (IPF). The gene discussed is TM4SF5; the disease is idiopathic pulmonary fibrosis.