In the present real-world data study, we examined patients with advanced or metastasised NSCLC and compared overall survival between a control group receiving a PD-1/PD-L1 inhibitor therapy and the combinatorial group receiving PD-1/PD-L1 inhibitors plus add-on Viscum album L. Our findings revealed that patients in the combinatorial group lived seven months longer in comparison to the control group (p < 0.001). The gene discussed is CD274; the disease is non-small cell lung carcinoma.