Expression of PD-L1 by HRS cells and TAMs. (A) Multiplex IF staining (40× resolution, case P6) for CD30 (top left, orange) to highlight HRS cells, CD68 (bottom left, magenta) to highlight TAMs, and PD-L1 (green) to show colocalization of PD-L1 and CD30 (top right, colocalization, yellow) and PD-L1 and CD68 (bottom right). Each image includes a nuclear counterstain/4′,6-diamidino-2-phenylindole (blue). (B) The relative amount of total PD-L1 per tumor (calculated as percentage of total fluorescence units), contributed by HRS cells (red) and TAMs (blue). The cases are ordered by the percentage of PD-L1 attributed to HRS cells, from highest to lowest. Cell lineage assignments (HRS cell; TAM) are based on pathologist-trained algorithms and include data from all fluorescent-channels (“Methods”). DAPI, 4′,6-diamidino-2-phenylindole.