CD274 and neoplasm: Most interestingly, when patients were stratified for PD-L1 negativity or immunohistochemical staining positivity (less or more than 5% of PD-L1 stained tumor cells in a section of at least 100 tumor cells), the median PFS was 14.0 months for patients with PD-L1 positive tumors in both the nivolumab-plus-ipilimumab group, and the nivolumab group.