PTEN and idiopathic pulmonary fibrosis: Since intrinsic toxicity was absent or very low in IPF fibroblasts treated with various doses (1 to 100 μM) of 3MA or CQ, we next measured cell viability in IPF fibroblasts expressing PTEN or dominant negative Akt in the presence of 10 or 100 μM of 3MA or CQ.