Poliovirus is structurally similar to other human enteroviruses (coxsackieviruses, echoviruses, and rhinoviruses), which also use immunoglobulin-like molecules to recognize and enter host cells. Phylogenetic analysis of the RNA and protein sequences of poliovirus suggests that it may have evolved from a C-cluster Coxsackie A virus ancestor, that arose through a mutation within the capsid. The distinct speciation of poliovirus probably occurred as a result of a change in cellular receptor specificity from intercellular adhesion molecule-1 (ICAM-1), used by C-cluster Coxsackie A viruses, to CD155; leading to a change in pathogenicity, and allowing the virus to infect nervous tissue.