CASP3 and neoplasm: Wang et al. discovered that when mouse breast cancer cells (4T1) were co-cultured with naive macrophages (Mφ) along with M1 macrophage-derived exosomes (M1-EXOs) or M2 macrophage-derived exosomes (M2-EXOs), the M1-EXOs prompted Mφ to adopt a Th1 phenotype, thus promoting the release of pro-inflammatory cytokines and a substantial rise in caspase-3 activity within tumor cells, which indicated enhanced apoptosis.