MFSD6 and infection: Although we observed that EV-D68 infection of skeletal muscle cells is largely facilitated by the presence of sialic acids in our model, EV-D68 entry to neuronal cells can be independent of sialic acids (16, 44) and can instead be facilitated by intercellular adhesion molecule (ICAM)-5 and major facilitator superfamily domain–containing 6 (MFSD6).