Given the recently described immunomodulatory role of cannabinoids, the importance of CD40-CD40L interaction in neuroinflammatory diseases, and the clinical and basic science studies suggesting that cannabinoids may be therapeutic in AD and MS, [21-25], we examined, in the present study, whether cannabinoids (primarily CB2 agonist JWH-015) could oppose microglial CD40 expression following interferon-γ (IFN-γ) challenge. Here, CD40 is linked to myeloid sarcoma.