IL4 and cancer: It was noticed that osthole prevented the infiltration of M2 macrophages in cancer and reduced the numbers of M2 macrophages in the spleen, In addition, osthole impeded the polarization of primary bone marrow cells into M2 macrophages, which was associated with the downregulation of the STAT6 and C/EBP β signaling pathways in the IL-4 induced RAW 264.7 cells [190].