CD4 and cancer: An exemplary mIF panel of commonly studied markers for the prognosis of patients with cancers, consisting of four lymphocyte markers, CD3 for T cells, CD4 for T helper cells, CD8 for cytotoxic T cells, and FoxP3 for regulatory T cells, and the checkpoint protein programmed cell death ligand 1 (PD-L1), which is mainly found on immune cells and inhibits T cell responses, was used [5].