Quantitative Spatial Profiling of TILs as the Next Step beyond PD-L1 Testing for Immune Checkpoint Blockade.

Analysis of tumor-infiltrating lymphocyte (TIL) functional states, particularly tumor-reactive PD-1T TILs, within specific spatial context, can serve as a biologically informed predictive marker of immunotherapy that may be superior to standard clinical biomarkers. High-plex quantitative immune cell phenotyping within their spatial context has tremendous potential in immuno-oncology. See related article by Hummelink et al., p. 4893.