We hypothesized that BRAF/MEKi would (a) increase TIL to day 29, (b) increase IFNγ signatures, (c) increase T cell homing receptor (HR) ligands, and (d) expand functional intratumoral tumor‐reactive CD8 T cells, but also that (e) increased T cell infiltrates would be associated with increased expression of PD‐L1, IDO, and arginase by melanoma and stromal cells. The gene discussed is CD274; the disease is melanoma.