This document provides a list of 10 core assays for testing compounds that modulate the immune system. The assays measure things like cell proliferation, nitric oxide release from macrophages, and cytokine release from splenocytes or human PBMCs in response to test compounds. Each assay is described in terms of the test model, turnaround time, minimum compound requirement, and standard reporting format. The assays will help optimize leads for anti-inflammatory, pro-inflammatory, or other immunomodulatory activities.