IL4 and neoplasm: In one study, Sakemura et al. first showed that CAFs isolated from the BM of patients with MM significantly enhanced MM tumor growth both in vitro and in vivo, potently suppressed BCMA CAR T-cell expansion and CAR T-cell degranulation, and significantly altered the CAR T-cell cytokine profile (increased inhibitory cytokines and growth factors: TGFβ, fibroblast growth factor 2 (FGF2), growth-regulated oncogene, IL4, IL5, MCP1, MCP2; decreased effector cytokines: IFNγ, GM-CSF, soluble CD40L, TNFα, TNFβ, macrophage inflammatory protein 1β) [148].