Andreis TF, Correa BS, Vianna FS, et al. - Researchers examined a series of Brazilian patients diagnosed with lung adenocarcinoma (LUAD) predominantly recruited from centers in southern Brazil for the frequency of somatic mutations in the EGFR, KRAS, NRAS, and BRAF genes, ALK, and PD-L1 expression. Via next-generation sequencing using DNA extracted from tumor tissue, they performed molecular analysis of the EGFR, KRAS, NRAS, and BRAF genes. ALK and PD-L1 expression were detected using immunohistochemistry. They analyzed 619 tumors and recognized KRAS mutations in 189 (30.2%), EGFR mutations in 120 (19.16%), and BRAF mutations in 19 (3%). ALK and PD-L1 expression were identified in 4% and 35.1% of patients, respectively. This work is identified to be the first study reporting on the molecular epidemiology of cases with LUAD from southern Brazil and the largest appraising the frequency of multiple predictive biomarkers for this tumor in the country. Also, a distinct mutation profile, compared with data originating from other regions of Brazil, was identified in this study.