HTR2A and infection: In a receptor-supported infection, JCPyV binds to α2,6-linked sialic acid receptors including lactoseries tetrasaccharide c (LSTc) [61,62,63] and/or non-sialylated glycosaminoglycans (GAGs) on host cells via the capsid protein VP1 [64] to initiate infection, and JCPyV then utilizes 5-HT2 receptors to enter the host cell [65,66,67].