Regulating monocyte infiltration and differentiation: Providing new therapies for colorectal cancer patients with COVID-19

The outbreak of coronavirus disease 2019 (COVID-19) is a significant challenge for clinicians, especially for immunocompromised cancer patients. By analyzing the impact of COVID-19 on the immune microenvironment of colorectal cancer (CRC) patients at the tissue level and single-cell level, we found that CRC patients are more easily infected by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), but promotion of infiltration and differentiation of monocytes makes them more likely to develop severe COVID-19. Because of the continuing activation of nuclear factor (NF)-kappa B and C-C chemokine receptor type 5 (CCR5) signaling pathways in monocytes, imbalance of macrophage polarization can aggravate the cytokine release syndrome. Therefore, regulating the infiltration and differentiation of monocytes is helpful for the treatment of COVID-19 in CRC patients.