EIF3K is a member of the eIF3 subunit K family. EIF3K is the smallest subunit of eIF3 and it interacts with a number of other subunits of eIF3 and the 40S ribosomal subunit. EIF3K is conserved among high eukaryotes, including mammals, insects, and plants, and it is universally expressed in human tissues. EIF3K is distributed both in nucleus and cytoplasm and colocalized with cyclin D3, a regulatory subunit of cyclin-dependent kinase 4 (Cdk4).