Peripheral Blood Mononuclear Cells (PBMCs) can be used in drug screening. In Part I from this series, we discussed how they can be used to assay drug activity including effects on proliferation, viability, apoptosis, inflammation, and migration in healthy and disease cell models. There are related assays available to measure the effects of drug treatment and, especially for researchers that prefer to use human samples, peripheral blood mononuclear cells are often the cells of choice (PBMCs) are often the cells of choice. The advantages of using human cells initially are immense.