CD63 is a tetraspanin family glycoprotein along with CD29 (integrin β1) (Supplementary Figure S3L), CD44 (a multifunctional transmembrane receptor) (Figure 4C and Supplementary Figure S2D, respectively), and LAMP (also known as CD107b) (Supplementary Figure S3E), which were also found to be expressed and hence packaged within control and infection EVs derived from CCoV-infected CRFK cells. Here, CD44 is linked to infection.