In order to demonstrate the effects of M1 macrophages on the MSC-dependent modulation of tumor growth, Jia and colleagues treated MSCs with condition medium derived from TNFα, IL-1β, and iNOS-expressing M1 macrophages (MSCM1-CM) and compared their phenotype and function with BM-MSCs that grew under standard conditions (MSCcontrol) [16]. Here, NOS2 is linked to neoplasm.