Peripheral Blood mononuclear cells (PBMCs) consist of different cells types including immune effector cells, such as lymphocytes, monocytes, NK cells, progenitor cells and stem cells. Immune effector cells play important roles in our body defense against infections and cancers. Percentage of different cell types in PBMCs various individually, PBMCs just can be used as biomarkers and research tools for the immune effector cell functions, immunological diagnostics and cell-based assays.