In the first instance, five different shRNAs targeting the endosomal protease, CTSL1 (Figure S6) reduced infections by 22–99% in the presence or absence of MBL, which lent credence to the validity of our assay because proteolysis of EBOV GP by cathepsin-L in the host cell endosome is a critical step for viral entry [45], [51]. Here, MBL2 is linked to infection.