NF1 and neoplasm: Multivariate cox regression analysis using BRAF/NRAS/NF1 mutation status, tumor stage and previous ipilimumab treatment as adjusting factors identified SOX2 as a negative independent predictor for OS in PD-L1 high patients (prenivolumab, HR: 5.67, 95% CI: 1.68 to 19.17, p value: 0.005; onnivolumab, HR: 3.69, 95% CI: 1.02 to 13.40, p value: 0.047) (online supplemental tables 3,4).