MASP2 and cancer: The SARS-CoV-2 N:MASP-2 association was also confirmed in lung tissue sections from COVID-19 victims but not cancer patients by an in situ proximity ligation assay (PLA), and the N protein:MASP-2 complexes (red fluorescent spots) were mainly distributed in pulmonary epithelial cells (Fig. 1f and Supplementary Fig. 1a).