NPC1 and infection: SREBP-2, SREBP cleavage-activating protein, membrane-bound transcription factor site-1 protease, and membrane-bound transcription factor site-2 protease were consistently observed as critical host factors, and other genes linked to cholesterol metabolism and trafficking, including LDL receptor, NPC intracellular cholesterol transporter 1 (NPC1), NPC intracellular cholesterol transporter 2, and ER membrane protein complex subunit 1, were enriched in screens of SARS-CoV-2, HCoV-229E, and HCoV-OC43 infection (56, 59, 60).