NRP1 and infection: More recently, it was found that furin protease is also involved in the infection process since SARS-CoV-2 contains an unusual for coronaviruses furin cleavage site in the S protein [6], and that the cellular receptor neuropilin-1 (NRP1, binds furin-cleaved substrates) potentiates SARS-CoV-2 infectivity providing also a pathway into the central nervous system [7]; SARS-CoV-2 may also utilize the putative alternative receptor CD147 (expressed in high levels in the brain) to infect cerebral nervous system [8, 9].