A correlation between ANPEP and ACE2 implies that ANPEP is relevant in SARS-CoV-2 cell entry (38, 39); Tyrosine-protein kinase receptor UFO (AXL) specifically interacts with the S protein of SARS-CoV-2 according to tandem affinity purification (TAP)–mass spectrometry analysis, and its overexpression in HEK293T cells promotes viral entry (40); Glutamyl Aminopeptidase (ENPEP), a type II integral membrane protein, is identified as a candidate co-receptor for SARS-CoV-2 based on the co-expression with ACE2, although its involvement in virus infection is not firmly supported (38, 41). This evidence concerns the gene AXL and viral infectious disease.