**5. Conclusions**

Herein, we confirm that higher *RAD51Bme* levels associate with PD-L1 immunoexpression, as well as with immunotherapy's efficacy, in an independent advanced NSCLC patient cohort. Prospective studies, with larger cohorts of patients and extended follow-up periods, are warranted to validate these results and determine whether the methylation profile of this gene might be a predictive tool for selecting patients that will benefit from anti-PD-1 therapy.

*J. Clin. Med.* **2020**, *9*, 1000

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0383/9/4/1000/s1. Table S1: Logistic regression analysis; Table S2: Multivariable analysis for progression-free survival; Table S3: Multivariable analysis for overall survival.

**Author Contributions:** I.M.G. and D.B.-S. collected clinical and pathological data, performed the methylation analysis and the statistical analysis and original draft preparation. P.L. and M.C. did the immunohistochemical staining for PD-L1. A.L.C. and J.L., and R.H. assessed PD-L1 immunoexpression. L.A. contributed to the statistical analysis and interpretation of data. A.R., M.S. and R.H. contributed to the design of the work. C.J. contributed to the conception of the work, review and editing. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was funded by the Research Centre of Portuguese Oncology Institute of Porto (CI-IPOP 68/2017 and CI-IPOP–FBGEBC-27). D.B.-S. and J.L. are supported by FCT—Fundação para a Ciência e Tecnologia (SFRH/BD/136007/2018 and SFRH/BD/132751/2017, respectively).

**Conflicts of Interest:** The authors declare no conflict of interest.
