CLDN1 and infection: This has been demonstrated for HIV-1 co-receptors CCR5 [107,114,115,141,142] and CXCR4 [117], the poliovirus receptor [128], the HCV receptor molecules CD81, occluding (OCLN) and claudin-1 (CLDN1) [104,143], and the AXL receptor for Zika virus in HeLa cell infection [131].