Interestingly, a rare synonymous polymorphism in RICH2 adjacent to the splice acceptor in exon 11 has been associated with slow progression to AIDS (Le Clerc et al., 2011), raising a possibility that the R19H tetherin polymorphism or differential expression of splice variants of RICH2 may affect tetherin's function in vivo. The gene discussed is ARHGAP44; the disease is AIDS.