XPO5 and Oral leukoplakia: In contrast, reduced XPO5 expression levels, attributed to the recurrent single nucleotide polymorphism rs11077 located in the 3′ untranslated region (3′UTR) of the XPO5 gene, have been closely associated with thyroid, liver, laryngeal, and colorectal cancers, as well as leukoplakia [17,18].