Eukaryotic initiation factor 3 subunit H (eIF3H) is one of at least 13 non-identical protein subunits of eukaryotic initiation factor 3 (eIF3). eIF3 is the largest eIF (~650 kDa) and functions to facilitate binding of the 40S ribosomal subunit to the 5’-end of cellular mRNAs near the cap structure (m7GpppN). eIF3H is a non-conserved subunit and part of the functional core of eIF3. It may function to stabilize the eIF3 complex and stimulate protein synthesis. Many cancer cell lines have been shown to express high levels of eIF3H, and it may have an oncogenic role in colorectal cancer susceptibility.