CSF1R and melanoma: CSF1/CSF1R signaling pathway has positive roles in macrophage biology, including survival, proliferation, differentiation, and phagocytosis.408 Stephen et al. reported that CSF-1R blockade with PLX3397 improved the efficacy of adoptive cell therapy (ACT) in the mouse melanoma model.409 CSF-1R blockade reduced the ability to unleash the immune-stimulatory capacity of TAMs with a skewing of MHC IIlow to MHC IIhi macrophages.