This 2018 multicenter observational study (PLoS ONE, PMID: 30148853) assessed the impact of adding Viscum album L. (mistletoe extract) to standard chemotherapy in 158 patients with stage IV non-small cell lung cancer (NSCLC). Patients who received mistletoe alongside chemotherapy had significantly improved median overall survival (17.0 vs. 8.0 months, p=0.007)