MKI67 and neoplasm: Treg require T-cell receptor (TCR) signaling for eliciting their suppressive function.17 18 We, therefore, sought to go beyond static cell markers of activation status such as CD69, Ki67 and CD25, and directly interrogate the dynamics of T cell signaling, to better understand changes in the immune tumor microenvironment (TME) occurring with HSV/BRAFi therapy.