STAT3 and cancer: In addition, a recent study by Roca et al. observed that macrophage-driven efferocytosis (a process of continually clearing of apoptotic cancer cells by immune system phagocytes during tumor progression) induced the expression of pro-inflammatory cytokines, such as C-X-C motif chemokine ligand 5 (CXCL5) by activating the signal transducer and activator of transcription 3 (STAT3) and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling.