Fig. 5.

a Representative images of immunohistochemical staining results. NSCLC tissue sections from the primary tumor as well as the corresponding metastatic site were stained for PD-L1. Tumor sections from two independent patients with PD-L1-positive tumor cells and PD-L1-positive tumor-infiltrating myeloid cells are shown (original magnification ×10 and ×40). b Quantitative comparison of PD-L1 expression on tumor and myeloid cells on large tumor sections as depicted in a of this figure. A paired analysis of PD-L1-positive tumor cells and PD-L1-positive myeloid cells in primary tumors and metastatic lesions was performed. IHC positive events have been depicted as % of total nucleated cells; paired two-sample t test was used to compare paired samples (n = 34)