CD274 and neoplasm: Despite the limited clinical activity of trametinib and pembrolizumab, we were able to reveal the feasibility of baseline tissue analysis by quantitative immunofluorescence, serial blood sampling, and peripheral blood flow cytometry to detect immune cell alterations in the tumor microenvironment and in circulation that may underlie more favorable immunomodulatory activity, particularly with lead-in sequencing of MEKi therapy followed by MEKi plus PD(L)1 inhibition.19