||tRNA (guanine-N(7)-)-methyltransferase subunit WDR4 is an enzyme that in humans is encoded by the WDR4 gene. This gene encodes a member of the WD repeat protein family. WD repeats are minimally conserved regions of approximately 40 amino acids typically bracketed by gly-his and trp-asp (GH-WD), which may facilitate formation of heterotrimeric or multiprotein complexes. Members of this family are involved in a variety of cellular processes, including cell cycle progression, signal transduction, apoptosis, and gene regulation. This gene is excluded as a candidate for a form of nonsyndromic deafness (DFNB10), but is still a candidate for other disorders mapped to 21q22.3 as well as for the development of Down syndrome phenotypes. Two transcript variants encoding the same protein have been found for this gene.