A study of tumour draining lymph node and primary tumour samples identified CD8+FoxP3+CD25+ effector T cells as a potential alternative biomarker for efficacy of PD-1/PDL1 blockade that merits investigation, with an association seen between the percentage this T cell subset and IFNγ response after PD-1 inhibition in vitro using single cell suspensions [49]. This evidence concerns the gene IFNG and neoplasm.